TW64 Smart Bracelet

7 May 2015


There are many different types of smart bracelets in the market.  The most common ones are branded under Fitbit,  Garmin,  Xiaomi but the most popular one appears to be a brandless bracelet called TW64.

What is a Smart Bracelet? 

Smart bracelet is nothing but an electronic counter that can be connected to the handphone and/or computer through a Bluetooth network for data logging. Various brands have come up with different functions  for such  bracelets.  Most use it to count the number of walking steps.  Others use the counter to work out calories consumed,   sleeping movements,  time alarms etc.  Many bracelets have a built-in time clock enabling the bracelet to be used also as a watch.   The more sophisticated ones like FitBit has in-built a height sensor,  enabling proper logging of step countings,  up and down a staircase.

What's Good About Smart Bracelet? 

1.  It takes record of your foot step, It will always help you to "challenge" your own self that you can always make longer and longer walk.   The recommended daily walking step is 10,000 steps for a healthy person according to American medical research institutions.  Once one has taken exercising to be a daily routine and walk or run  10,000 steps,  one would feel very uneasy to stop walking

2.  If the bracelet counting is website based, it will enable your bracelet to be "monitored" by the vendor like FitBit.  One might be able to use the records to get premium discount from some Health Insurance Companies.

What is TW64 and why it is popular? 

TW64 has been marketed under several brand names.  It has a twin 64K RAM and a 64K ROM all inside a Quintic 2021 system-on-microprocessor chip (SOC) which consumes ultra low power.  The abbrev "TW" could stand for the word TWIN.  TW64 is popular because it is one of the most affordable bracelet that has almost every function of the more expensive cousins.      

What are the main functions?

1. A 24 hours clock with running dates and a battery counter
2. A pedometer that registers walking step counting which is used to calculate the distance traveled and the calories burnt.
3. Other functions such as vibration reminder,  alarms,  sleep monitoring etc

Construction 

The chip,  Quintic 9021,  is enclosed inside a plastic casing measuring about 17mmx40mmx10mm.  The back case can be easily removed by 4 small screws to expose the inside electronic as shown.  Unlike other bracelets  it  allows the battery to be replaced.

Synchronising 

Like any other smart bracelet,  one can synchronise TW64 to the Android or Apple handphones through bluetooth using a free software called "MOVNOW plus", downloadable from Google Playstore or Apple Store.    Unlike Fitbit or other more sophisticated smart bracelet,   MOVNOW is not web-based and therefore,  could only be synchronised using handphones.

Performance 

The TW64 was tested with a full charge and compared it against a Fitbit Flex by wearing them together on the same wrist as shown.

The sets are then taken for a 6 km walk and the results are compared as shown

It can be seen that TW64 and Fitbit Flex have quite similar step counting.  It is well within the 10% error range.

The Battery and capacity 

The battery is a lithium-ion polymer type of either 40mAH or 60 mAH capacity. The test set came with a 60mAH battery and the vendor claimed it is able to handle  at least 7 days usage and 100 days standby.  After 5 days’ testing,  the test set still have 3/5 of the charge as indicated by the battery indicator.

Pros and Cons

Pros

1. It is very affordable,  priced around SGD$20/= including shipping from Q0010
2. It is not bad looking.  The bracelet material feels like silicone and has a look like FitBit Charge or other more sophisticated and expensive model
3. Long lasting battery that can be used for 7 days or more on a 60 mAH battery
4. Can be used as a watch
5. The battery is replaceable
6. Can be used without the handphone

Cons

1. The software is not web-based and therefore,  the data loggings or recordings might not be accepted by Health Insurance company for any discount in health premiums
2. The vibrator is soft and the vibration might not wake up some heavy sleeper ;  moreover,  the wake up alarm will sound only once.
3. It is only splash proof;  meaning,  cannot be worn for swimming.
4. Must synchronise to the phone regularly or the data would be lost. However,  the bracelet can store some data over nights for next synchronisation.

Things to watch out when buying TW64 

1. There are many brands offering various model of TW64.  Some are older model that can only used for older Android phones or iphones that have Bluetooth of 3.0 or lower
2. Go for TW64 which has 60 mAH battery as the battery will last longer. 

Things to watch out when using TW64 

1. The weakest part is the 3 charging contacts.  Clean them every time with a paper tissue after each long walk to get rid of the sweat.

1. Do not wear it for swimming though there is no problem wearing it during showers.  
2.  

QN902X Application Notes

The application notes on QN902X can be found here. 

Instantaneous Heater – Electrocution in the Shower

2 September 2014

There was a report that a Singapore teen was found dead while taking a shower. It was not immediately known if he was electrocuted or just scared to death as an electrical outlet that was connected to the instantaneous heater was shown charred in this picture.

Observation

There was no further report on the death but it was said the family just replaced the instantaneous heater themselves. They found the boy dead, lying on the floor when they forced open the bathroom door after hearing the boy's screaming. The resuscitation did not help the poor child.

The picture showed that the heater wires, run on ordinary 3 core cable, might be directly connected directly to a heater switch which could have burnt out.  This did not quite indicate the boy was electrocuted.

The heater switch is also not a common one that use double-gang socket outlet box. The picture also shows that the house wiring is a very old type with exposed wirings running on the surface using wood battens. This sort of wiring type is only found in very old HDB flats or perhaps in SIT flats that have never been replaced. But this flat in Block 1 Hougang Avenue 3 is a HDB 3 room improved unit which was built in the 70/80.

It was also reported that the socket outlet box was installed inside the bath room.  This is not allowed under the present electricity codes in Singapore.

What could be wrong?

There may be many reasons causing the boy’s death. It is not known until the investigation has been completed.

But from the picture, it may be clear that the wirings and system was not a typical installation in HDB’s flat built in the 70/80. This suggests that the owner could have re-wired the installation.

PUB, the former utility board, made the installation of earth leakage circuit breaker (ELCB) a mandatory requirement for every new residency electrical installation in the 70s.

If the boy has been caused by electrocution, it may be highly possible that either the ELCB is not working properly or the re-wiring of the apartment has removed the ELCB.

What is an ELCB?

An earth leakage circuit breaker (ELCB) is an electrical switch that can sense current flow or leakage of electricity and trip the main switch to the apartment before anything damage could happen.

Most Singaporean homes are installed with such ELCB that can trip when the earth leakage is more than 30 milli-amperes.

In the past, the ELCB must have saved many innocent lives. If it is true about the electrocution,  this poor boy would have been saved if the ELCB had worked and trip the electrical supply.

Could it be a failed ELCB?

The ELCB could fail to operate because it is basically an electro-magnetic switch with mechanism that might get stuck in the closed position during operation. It is for this reason that all ELCB will have a test button.

Testing of ELCB should be done regularly. The best is once a month. This is because ELCB or the main switch board are often enclosed somewhere out of view and may subject to all sort of environmental exposures including possible moisture attacks,  rusting the mechanism.

Besides Testing ELCB, what can be done?

One could ensure always that electrical appliances are connected to the earth so that if there is any electrical leakage to earth from the appliance, it will first trip the electrical main before any human could touch them; also, if there is any human contact, the current created will have enough power to trip the ELCB.

How to ensure there is a proper earthing?

Invest in a multi-tester that would cost not more than SGD$30 from most electronic shops.  The meter is also available from many $2/= neighbourhood shops with a separate price tag.

Set the tester to the lowest ohmic range, say 1 to 100 ohm. Using one test lead touching the metal part of the appliance, the other test lead touching any metal part of the water pipe or tap. The meter should show some readings around 10 ohms and below. If it is more than 50 ohms, most likely one would have a faulty earthing requiring attention or rectification.

In the case of instantaneous heater, using one lead touching the metal part of the piping connector of the shower head and the other lead touching directly to the water facet that is connected to water heater.    

In case where instantaneous heater has a PVC outlet connector that does not expose the metal part of the heater such as those shown here having an insulated PVC connectors,  carry out as follows:

First, switch off the power supply, then remove the outer protective casing of the heater (usually fixed onto the heater with a bottom screw). Using one cable lead touching the metal boiler unit or any other metal part and the other lead touching the water facet directly.   When fixing back the casing, make sure it is fixing back to the original position.

Why test cable must touch water pipe or facet?

It is a mandatory requirement in Singapore that all wiring installations must have their earthing bonded to the water piping at the incoming mains.

By having one lead touching the metal part of the appliance and the other lead to the water pipe or facet, one can test roughly the integrity of the earthing system within the apartment.

If the earth readings are more than 10 ohms, it is good to check the earthing of the appliance or the actual electricity earth for safety sake.

The electrical installations in Singapore are always installed with an effective earthing resistance having less than 1 ohm.  There should be test reports submitted to the authority.

What if the water piping has a section consisted of PVC?

Water pipings are mainly metal pipes but sometimes, a section of PVC may be inserted. It may give false reading especially when there is no water in the pipes. If there is water, the multi-ohm meter should still give some good readings because water is electricity conductive. If there is any doubt about the integrity of the earthing, place the test lead to the water pipe before the PVC section.

What if the Ohmic reading is Still high?

Try pulling a power extension cord that has an earthing connector from the nearest power socket outlet  to somewhere nearer to the heater and measure the resistance between the extension cord's earth and the heater's earth.   If the reading is still high,  there is a poor earthing connection to the heater and one should call an electrician to fix the problem immediately.   This high resistance readings could be caused by the Teflon plumbing tape being used to seal the  pipe joints of metal pipes especially when there is a repair on the existing piping system.

Update 1:   2 Sept 2014

This picture showed clearly the heater was connected to a 3 pin plug.   Understand the switch socket outlet of a double gang type was removed by the Police for investigation.  This switch socket outlet, installed outside the bath room,  was connected to the supply using another 3 core cable.  The wiring is an illegal addition according to the local codes which required all fixed wiring (e.g onto the walls) must be carried by licensed electrical worker e.g. an electrician and proper wiring method consisted of conduits or trunking should be used.  No flexible cables should be used.

What can I do if the house does not have an ELCB installed?

The Electricity ACT 1974 mandates the installation of ELCB in all new apartments including HDB flats.  Those built before this date might not have ELCB installed as a standard.  One should install the ELCB immediately for these electrical installation at the main switch panel.  It may cost around SGD $200/= including labour but it will save some life. 
However,  one could also install power socket extension plug with ELCB protection.  In such case,  it is better to check if the power socket extension plug has proper testing certificate from recognised institutions.  This extension plug might not be cheap.

Update:  The Coroner's court 

The Coroner's court in March 2015 found that the boy could have come into contact with an electrically energised metallic shower outlet hose that was attached to a water heater.   The court added that the boy's father installed the water heater about three months earlier. The simple installation work did not fulfil the strict definition of 'electric works' regulated by the Energy Market Authority.

http://www.straitstimes.com/singapore/courts-crime/teenager-electrocuted-in-shower-died-of-misadventure-coroner-finds

27 March 2017

 Installing New Instantaneous Water Heaters


1.  Never trust anyone whosoever install the electric instantaneous water heater for you. Even if it is a qualified electrician or LEW, they might make mistakes.   He may also be color-blind making wrong wirings;

2.  Make sure you see that person who install the water heater test the earthing system in your present. If possible, ask the person to perform a earth leakage test using method just described to ensure that your house's earth leakage circuit break (ELCB) or residue current circuit breaker (RCCB) is working properly;

3.  Also make sure the water heater has PSB/SPRING – Singapore or approved testing label.

Novita Garment Steamer Repair

26 July 2014

Turning on the Garment Steamer one day, it tripped the earth leakage circuit breaker (ELCB), cutting off the electricity to the whole apartment. The steamer is Novita brand and the model is SS23. It was about 14 months old and the warranty has just expired. 

The name plate reading is as shown

What could be wrong?

Immediately, a corroded heater unit came to mind. Water or moisture could have found its way to the heating element, thus causing the short circuiting of the line to the earth and the tripping of the ELCB.

However, after opening up the unit for inspection and testing, it was found that boiler unit was covered up completely with calcium scales inside and outside of the heater unit but the heater unit was found to be in good condition. The moistures soaked up in the calcium scaling could have caused the ELCB to trip.

Opening Up

The unit is attached to lower carriage by about 8 screws. After releasing the 8 screws and opening up, one can see the plastic boiler unit and the heater unit. The boiler unit is held onto the upper case by 4 white screws and the heater unit is held onto the boiler unit by 6 black screws. A silicone gasket at  the rim of the heater unit and the ring bracket provides the water sealing.

In this particular unit, one could see that the base of the boiler is covered by whitish calcium scales. It may be formed by steams releasing through the gasket under the steam pressure. The scales may have been built up on the base of the heater unit over the one year period.

Insulation Testing Before Dismantling and Cleaning

It is good to use a multi-ohm meter to test the insulation resistance of the heater element after clearing and cleaning up all the terminals using industrial thinner or spirits or other suitable solvents. One should get some reading of more than 200 K-ohm before proceeding to strip the boiler unit. Should one get a reading lower than 100K-ohms, it is likely that heater unit could be bad and may require replacement.

In this particular steamer, the heater unit was found to be in good condition except for the calcium scaling at the base which had lowered the insulation resistance.

Removing the Boiler Unit

To clean up the calcium scale and cake completely, one would have to remove the 4 white screws of the boiler unit and all the wirings attached to the thermostat and the heater unit. Note down where and how  each wiring is attached and connected to before dismantling the wirings.

Unscrewing the plastic nuts on the top cover to remove the whole boiler unit. After that, unplug the silicon hose.  After that,  unscrewing the 6 black screws on the heater bracket that holds the heater unit to boiler shell will remove the heater unit completely. Please take care not to damage the silicone gasket which can be re-used.

In this particular steamer, the dome shaped heater unit and its base were completely covered with calcium scale and cake.  

Reasons for Calcium Cake and Scale forming

The use of ordinary tap water which contains a lot of minerals especially  rich in calcium might have cause the built-up of the calcium scales and cakes.

If the water remained in the boiler unit is allowed to dry without draining out after use, calcium scale and/or cake will start to form.  This is true when the calcium concentration in the water exceeded the soluble limit.  Further,  the evaporation of water,  turning water into steam will leave concentrated calcium elements behind in the boiler unit to form the scale.   This calcium scaling or caking is a  common problem in all boiler units.

How to Prevent Calcium Scaling and Caking

Always use soft water that has little or no mineral. If one has air conditioning unit in the apartment, the condensate water will be an ideal soft water for such usage after filtering. Using PUB's Newater is another source; besides,  there are  other drinking water that has been filtered to get rid of most minerals especially calcium carbonate and related calcium products.    Should ordinary tap water be used,  always drain the water completely after use and never leave any water behind to form the scales and cakes.

Cleaning the Heater Unit and the Boiler Shell

The boiler shell is made of plastic. There was no de-scaling required except for removing the calcium cake formed at the shell.

The heat unit on the other hand will require a complete wash down using damped cloth soaked in vinegar, then  brush over with an used tooth brush and thereafter,  flush in the running water.

Avoid using shape and hard object such as a knife to remove the scales except when clearing away the scales at the rim of the heater unit for proper seating and sealing of the silicon gasket.

As running water will be used for cleaning, it may be necessary to masking tape the heat terminals to prevent water seeping into and damage the insulation of the heater.

Assembly

1. Reverse the dismantling procedures except for:

1. Applying silicone grease onto the silicone gasket and “polishing” the base of the boiler with silicone grease  to prevent future scaling taking place;
2. Heating and drying up the heater and the boiler units with a hair dryer, making sure there is no water at the wiring terminals

2.   Measure the insulation resistance between the wiring terminal of heater unit and the metal base,  making sure the insulation resistance is at least 200 K-ohms; if necessary, use hair dryer to dry and chase away the moister in the heater unit.

Starting Up After Repair

Some water moistures or molecules may have found its way into the heater unit if the insulation resistance is less than one mega-ohm.

These moisture will have to be “purged” out; otherwise, it may trip the ELCB again when the unit is turned on for testing.

To “purge” the moisture, use an adaptor without the earthing connection or otherwise, remove the earthing cable temporarily to prevent ELCB from tripping.

Exercise caution not to touch any metal part of the steamer in the absence of the earthing cable as these metal parts may be alive without the earth wire connection.

Fill the steamer with some water, then switch on the steamer.  Let the steamer run  for at least 5 to 10 minutes; thereafter, measure the insulation resistance of the heater unit again using the ohm meter. One should get insulation resistance of more than 1 Mega ohm between the heater element and earth; otherwise, repeat the process.

While draining out any water left in the boiler, make sure to take necessary precaution as the water in the boiler may be very hot.

Schematic Wiring Diagram

Unique Digital Clock with 4 functions

24 July 2014

This unique looking digital clock sold by IKEA Singapore for less than SGD$5/= has 4 functions;  it has a digital clock,  an alarm,  a digital temperature and a digital timer.   It is made in China and called KLOCKIS. 

The Construction and usage 

The clock measured  about 70 mm square and 30 mm thick.  It requires 2 AA size battery for operation.    The current draw is as follows  

Working Display with  LED light off: 7 to 13 uA

With LED light on : 8-15 mA

Alarm : 22 mA 

Therefore,   a set of  battery should last for a few months if it is not often used as an alarm clock. 

The 4 functions are as marked in the clock surface and the functions are selected accordingly when the marked function is at the top.  The LED light will change color  momentarily for each display,  red for clock,   blue for temperature,   green for timer and light blue for alarm. 

The Timer

The Clock

The Temperature

The Alarm Clock

The clock has only 2 setting buttons at the back, one for setting the digital and the other for adjusting the display.  The button only allows forward adjustment.   

The alarm will set off in any display function once it is set.  There is no alarm button to silence the alarm.  The alarm can be silenced by turning the clock from one function to another.  

Conclusion

This clock is useful in the kitchen,  bedroom and in fact anywhere. For SGD4.90,  there will be many satisfied customers.

User Manual

Wyatt card 32L Battery Operated Water Pressure Washer

30 June 2014

This battery-operated car washer was sold for about $45/= including shipping at Q0010.  It is suitable for most water cleaning jobs in cars as well as in homes.   It is a handy pressure cleaner for washing the air-conditioning outdoor units which hand-operated pressure washer just could not do the work properly.  The delivery was the next day which is pretty fast.  

Pros

1. It has a 32-liter water tank;
2. It can deliver up to 1.2 mpa (130 psi) water pressure; Its motor is rated at 3.0 mpa (430 psi)
3. It is potable and equipped with all cleaning accessories,   such as a water brush,  hose,      and water gun;
4. It has auto-start and stops function triggered by pressure sensing
5. It is safer to use as it operates from a 12 volt supply which requires 4 to 5 amperes for normal operation;
6. It is constructed from ABS plastic that can withstand rough usage.

Cons

1. A full tank of water can be quite heavy to be carried around without having a trolley, But one can always carry a half-full tank then fill it full tank with a pail of water. 
2. Water can leak from the bottom of the tank when the suction hose is not properly secured;
3. The manual is written in Chinese.

Compared to hand pump washer

Pros

1. It has a larger water tank;
2. It can deliver at least 6 times the water pressure for cleaner wash;
3. It does not have a pressure tank that can easily crack;

Cons

1. It can be heavy to move due to larger and heavier water tank

Compared to mains operated pressure washer

Pros

1. It is safer to operate using 12 volts supply;
2. It does not require any hose for connection;
3. Can get supply directly from car batteries;
4. Easy storage as it comes with a box 

Cons

1. Refilling of water is required from time to time;
2. Needs 230 volts to 12 volts power adapter for mains operation; 

Construction

The box is quite pleasing in appearance and comes with a toolbox that can store all the components and accessories.  The box can be easily stored away in the storeroom.

The Pump Compartment

Hidden away from view is the pump compartment that is located underneath the water tank.  It can be opened for inspection by removing the 8 screws that held the cover as shown here

The 12-volt motor is held onto the bottom of the tank by a set of 4 screws.   

Testing 

It is noticed that the tank must be almost half full before one can prime the pump to start using the washer. 

When filling up the water,   water started leaking from the bottom of the tank.

 

Why the Water Leak? 

Water was found leaking from the flexible silicone hose that was only  ‘threaded” through the compartment hole without any adaptor or connector. The hose was connected to a non-return strainer located inside the tank.   

The design requires the flexible hose to be properly straightened so that the water seal is maintained by the wall of the flexible hose.  Water can leak through the ‘kink” if the hose is not properly seated to seal the hole as can be seen from this picture.

What Can be done?

Temporary fix

Pull the silicone hose carefully with a light force from the strainer inside the water tank to straighten the hose.  This will make sure that the “kink” on the hose will be straightened out.  However,  as the hose is flexible and can collapse under suction pressure,  the “kink” will soon re-appear after some usage.

Easy Permanent fix 

Cut a piece of a plastic tube with a diameter of around 7mm.  Test if it can easily be inserted into the hole to expand the hose to form a tighter water seal between the compartment hole and the hose as shown.   While testing the correct size of the plastic tube to be inserted,  unleash the hose clamp and pull the hose from inside the tank until one can try to test the fitting of the plastic tube.  Try not to pull the hose out totally as it could be a pain to re-insert the hose again.

While installing the plastic tube,  always make sure that the plastic tube would be larger than the inlet of the water pump so that it would not be sucked into the pump should it become loose during operation. 

Performance  

The washer has a pretty strong water pressure that can even strip off the paint work on a PVC pipe as can be seen from this video.
 

The pump would stop and start automatically just like any electrically operated pressure washer.  It has also a polarity switch that can switch over the polarities automatically without worrying if one has correctly connected the 12-volt cable in the right positive or negative polarities.   

The washing operation is quite smooth although one would have expected the soft suction tube to collapse occasionally when there is not enough water in the tank.  However,  it should not have caused permanent damage to the pump.

Operating from a main operated power adaptor

The washer can be operated from a 12-volt power adaptor which must have an output rating of at least 6 amperes. 

Conclusion 

It is a cost-effective car battery-operated water pressure washer which is well designed except for the leaking flexible suction hose which can be easily fixed.  Other battery-operated water pressure washers would cost easily more than $100/=.  

Turning Food Waste into Compost in High-Rise Apartments

5 June 2014

In Singapore, more than 90% of the populations live in high-rise buildings.  Some might have luxury of balconies,  most just have common corridors for planting some plants and flowers in pots.  Not many have backyards that could be used to make compost which usually emits foul smell.  Many resorted to buying  pallet fertilisers from the shelves which can cost them a bomb over a longer period.

What is compost?

It is an organic fertiliser made from waste fruit peels,  skins,  vegetables and other organic foods.  They are usually left to decompose for a period of about two to three weeks until they are turned into partly a soil enriched with organic fertilising elements. 

How Compost was made?

Many in the net taught us how to make compost at home; some are suitable for high-rise buildings while others are not. Some used compost bins and some used earthenware to keep and make the compost. What they normally teach us is either to keep the waste in the bins or earthenware together with some dry leaves. These bins/earthenware might give out odours or scents and other rotten smell filling the whole apartment. 

What is the better method? 

Instead of bins and earthenware,  the better method would be to use plastic bag which every household will have plenty when they shop at the Supermarkets.  Instead of keeping the waste together with dry leaves,  one must treat the waste such that it will not give out lots of rotten smell.   

Preparing the compost 

1. Drying the waste 

A good method is just putting the waste under the sun. This will unfortunately attract a lot of small food flies and sometimes,  big flies which some may have strong objections.  However,  one can cover the waste with fine net mesh to keep away the flies as shown.   

It is always good to cut the waste into small pieces for easy spreading and for drying under the sun.

The other method is to fry the waste on a frying pan so that the heat will not only dry up the waste for safe keeping in the plastic bags,  it will also kill  the bacteria inside the waste.  

2.     Grinding the waste (optional) 

It would speed up the compost making if the waste is grounded every time for storage.  It is not quite necessary if one is prepared to keep the waste for a longer period than 3 weeks and not too fussy about the smell that may be emitted from the compost.   One could further fry the grounded waste to get rid of more moisture.

3.  Storage  

The success of the compost making will depend on how one can cultivate the anaerobic bacteria that will consume the waste and turn the waste into soil enriched with organic fertilising elements.  This is where plastic bags will come in handy as one can easily mark the plastic bags to keep track of the storage period as well as ensuring that there will be little exchange of oxygen that will kill the anaerobic bacteria.  

1.     Find a good plastic bag.  The shopping plastic bags are so thin that they would usually have small holes here and there.  To plug these holes,  inflate the plastic bag by blowing air into it and plug up the holes if any with masking tape. 

2.     Put the dry waste and spread it across the bag as a layer,  then cover it with 2 layers of ordinary soil. Active soil with some anaerobic bacteria in it will populate and digest the waste much faster than those inactive soil, idled for some period. 

3.     Mark the plastic bag with dates and keep in storage until 2 to 3 weeks later. Additional layer of same proportion of waste can be added to the plastic bag until it is full.

Precautions in Handling Compost

There were reports that some farmers in Australiaand New Zealandwere killed by legionnaire bacteria when they handled the compost with their bare hands and did not wash their hands afterwards.   

It is good to bear in mind that there would be many different type of bacteria in the soil and compost.  Legionnaire bacteria are one of such bacteria that could populate well under anaerobic condition especially when the waste is still wet before storage.   Legionnaire bacteria are commonly found in air conditioning cooling towers and also air conditioning condensate pipes and water storage if some part of the water is kept under an anaerobic condition. 

It is good to wear gloves as well as breathing mask when handling the compost as bacteria could fly around when the compost are being churned and mixed.  It is always advisable to wash the hands with soap and clean water each time after handing the compost.   Let the soil expose to the sun for a few day before handling them with the bare hands.

Review on Omron Blood Pressure Meter

2 June 2014

Bought this meter from Q0010 for less than SGD$90 including $4.50 shipping charge.  This meter was delivered within 4 days which was considered fast. The first impression was that it looked better than the Osim icheck 100 blood pressure meter I had had for almost 2 years.  I bought this Omron meter as a replacement for the Osim meter as the latter had not been giving accurate readings.  I had  to rely on manual method to get the readings done. 

Model and Features 

The model is BP742,  a lower 7 series of the Omron range.  It was manufactured in Vietnam.   It came standard with 3 main readings,  the systolic,  diastolic and the pulse/min reading.   The screen reading is quite big with characters measuring about 15 mm tall per character which is very easy to read for elderly who has vision difficulties.

Besides the bigger characters,  this Omron meter also has some other features which are useful:- 

1.   Memory storage for 2 persons.  Each person can store up to 30 readings that include time and date signatures.  The memories can be reviewed easily by selecting the front buttons. 

2    averaging the readings taken in the last 10 minutes 

It also comes with hypertension warning indicator. 

It is running on a set of 4 batteries giving a total of 6 volts supply.  It  did not come with a storage bag and a 6 volt adaptor.  The manual came together with the set are just description on how to use the meter. 

Inside the Meter 

Those guts inside the meter are also quite standard.  It has the following components 

1. The LCD display board
2. The electronic control board and the pressure sensor
3. The Pressure pump
4. The pressure header
5. The solenoid relieve valve
6. The orifice capillary valve

How it works

When the start/stop button is pressed,  the electronic control board will start the pressure pump to pump air into the cuff via the pressure header.  The pressure sensor in the control board will give the readings to display on the LCD display board.   At the same time,  air will also be released continuously through the orifice valve at constant speed as the solenoid valve is slammed shut.   The pressure pump will be shut off once the electronic does not detect any pulsing signal through the pressure sensor and the air is allowed to discharge through the orifice valve until the pulsing pressure is detected again and subsequently,  disappears. This is when the solenoid valve will release the air completely and the LCD will display the reading. 

Accuracy Checking 

The meter was checked against a pressure dial gauge which had been calibrated before against a mercury pressure meter. The meter and the dial gauge are then connected in parallel to measure the blood pressures.   

The pressure readings recorded were almost the same for the two types of meters as shown in the following table. 

Dial Gauge (mmHg)	Omron meter (mmHg)
20	20
60	60
80	82
100	103
160	162
180	182

The measurements of systolic and diastolic pressures were also within close limits when compared between the manual dial gauge using stethoscope and the automatic Omron meter.

Overall Verdict

 

It is a cost effective and accurate blood pressure meter that will keep customers happy for a smaller sum.

Safe to Buy Stocks with Little or No Float?

26 May 2014


Someone has been selling on the idea when there is very little float,  for example in the case of China Fishery Group Pte Ltd (CF,  BOZ.SI) in SGX,  there would be little chances of prices falling drastically should there be a sell down;  it is pretty safe to buy and keep so to speak.  Let examine a scenario how things can always happen when everyone is complacent.  That is usually how the contrarians will profit. 

Security Lending and Borrowing 

Like most major bourses in the World,  SGX allows also security lending and borrowing.  This is done through the Central Deposit Pte Ltd (CDP) that keeps the registries of all stock and shares traded in SGX.   Any member of CDP can lend and borrow any amount of a particular stock exceeding a minimum lot  provided there are agreed lenders and borrowers.  The script lenders will get 4% interest which is  better than nothing sitting pretty in the CDP’s vaults.    Once lent out, the lender will temporarily lose the ownership of his scripts although he still has all the rights such as receiving dividends, voting and other rights.  The borrower who becomes the temporary owner of the scripts will pay 6% for the borrowing.  He  can do anything with the scripts such as for “covering” its risk in a margins trade or for shorting purposes.  Under the agreement,  the lender can still sell its stocks and CDP will make separate arrangement to cover until the period of the "loan" is over.

Margin Trade

Margin Trade is like borrowing money from a broker or an institution such as a bank to purchase stocks. It can be treated as a loan.   Margin trading allows one to buy or sell more stocks than one can possibly own using the normal channels. They will need little capitals because of the leverage,  sometimes,  can be more than 1 to 10; in other words,  one can buy $10/= worth of stock with just $1/=.  Margin Trades are governed by laws structural wise but not in the actual trades.  One must have the qualifications to become a margin trader and the brokers or institutions will need to comply with some rules and regulations.   In a way,  Contracts for Differences ("CFDs")  is one derivative of margin trades.

 A Possible Scenario

Trader A,  a prominent business man,   thinks that CF is a good stock and it will move up but he could get little through the normal channel because not much was traded in SGX daily due to very little float.  He goes to his brokers or his banks.  Because he is a big customer who can back up his  “loan  of shares” with his collaterals or cash deposits,  the brokers allow him to purchase the stock on a margins trade.  

Assuming CF went up daily,  Trader A will make tons of money because of the leverage.  There will be no top ups required for his margins trade and he can withdraw some of his winnings.  Assuming CF went down,  Trader A will be asked to top up the margins.  Now further assuming that Trader A could not do the top ups in time,  the brokers will have to right to “call” his margins trade with the brokers recovering the cost from Trader A.

Now,  one may ask how do the brokers “call” the margins.  You guess it right.  Besides threatening to confiscate Trader A’s  collaterals,  the brokers can also through some means,   taking the opportunity to “short sell” CF using  the borrowed  scripts.  They can always sell CF  in a Zombie way (selling without feeling of losses),  making “a pile” while Trader A will be footing the final bills.

Characteristics of Zombie Sale

Besides these zombies sale has no feeling of losses,  the brokers and institutions are also not in a hurry to buy back and return the scripts.  It will usually take a long time before the price can rise again.

 

Catching the falling knife

It has become an even better ground for the brokers to short sell the market using borrowed scripts when SGX started clamping down the short sellers.  First, they said one cannot short-sell without covering within the day; otherwise, the buying-in will start on T+2.  Then, they modified later to say one can short-sell but must cover within T+3.  The buying-in by CDP will start at T+4.  

Either way, greedy investors now turned to CFD or margins trading where investors are allowed to buy or short any amount within the scope of  “limited funds and collaterals ”.  These are all performed and controlled by the brokers and Institutions. 

When the brokers and Institutions started making margin calls and afterwards, short selling the market,  it will create a falling knife pattern where many retailers will trade for profits by buying at low,  then selling at high.  How much will these retailers profit will depend on when the brokers and Institutions will complete their zombie sales.

The final winner is none other than the brokers and the Institutions as they will have the  control of the market and also enough collaterals to cover the damages and losses.  The retailers who rushed in to buy up the stocks think it was a bargain might contribute more to their winnings .