Hobby Projects - Insulation tester, LED Circuits, Meters.
Showing posts with label Schoodles-2. Show all posts
Showing posts with label Schoodles-2. Show all posts

Friday, December 17, 2010

Ni-Cd and Li-ion Battery charger Generic

This is a Generic charger that is made by many brands, the circuit is an approximation of all. Some improvements suggested. Some brands in europe and usa also use this circuit. This works well, but may not be in the best interest of battery life. The cost of the charger needs to be low. So this design or configuration is popular.

Battery Level Indicator 

Ni-Cd and Li-ion Battery charger Generic

The more care you show in the charger's battery charging and discharging; the longer its life. Today i manage my UPS batteries manually, both charge and discharge. The batteries are expensive, there is no better way, that is affordable.

Switching Battery Charger with L296 - del20031

Take batteries seriously - this is the source of transportation, power, solar energy reservoir etc. More so in the Future - start here Battery University.

Saturday, August 14, 2010

Mains Adapter 230V AC 50 Hz to Rectified DC

Mains Adapter Converts 230V AC 50 Hz to Rectified DC which replaces a Battery Pack. It was also called Battery Eliminator by older generations as it was used to save Battery Cost in AM Radios.

Mains Voltage and Power Circuits

Mains Adapter 230V AC 50 Hz to Rectified DC

The most important product safety aspect is the transformer, may it be well isolated, may it use a split bobbin, may it have a visible insulation between primary and secondary. May the thin primary wires not slip into the secondary .. when not using split core. Use a Layer to layer insulation for better safety. Use a nice laminated thin sheet alloy core stack, then no hum and no heat. vacuum impregnate magnetics. May the customer be safe and sound.

Power Electronics & Solar Energy

Remember only if we keep a customer alive, he will buy more products. From medicines to transport, from bread to gadgets. The customer is the most valuable asset. If he is kept Alive and Healthy and in a Cheerful mood … He will Buy !!

Torch or Flashlight Circuit Improvements

I fixed a China Torch with New LEDs and a Diode, it failed probably on a drop shock, the battery wire cut … then when put on charge Few LEDs went bad, as battery was absent in ckt.

The Success of the LED Lamp

Torch or Flashlight Circuit Improvements

design review - 1.5uF voltage rating can increase like 440V AC. A current source with low dropout voltage would be great but it builds the cost. The wiring has to be robust. A diode added to keep LED current within some limits on battery overcharge.

LED Lighting - The Future is Here

These type of Torches and Lanterns should not be Turned on when charging. This may blow the LED Array. As long as the LEDs have a constant current flowing through them they are safe. It could be anywhere between 10mA to nearly 25mA depending on the type. LED Arrays can be in parallel or series or a combination of both. The datasheet has to be studied for the high current types.

Never subject these LEDs to a Reverse Bias voltage that is very high. It means reverse polarity. Never allow the current to go so high that it overheats the device, reduces longevity or even damages instantly at high current. These devices survive short pulses of high current. Hence PWM is a way to protect devices and arrays too.

Friday, August 13, 2010

Mains Powered China Emergency Bulb

A typical Mains Powered China Lamp. On power down, LED light turns on for around 1/2 hr. Gets damaged on lightning activity and wide (uS not nS) transients above 300V. Drawing may have error.

Mains Powered China Emergency Bulb

Many products and components were made over the last 10 years with less regard to voltage and current ratings and product safety.

The circuit design is not everything, engineering the product for reliability, usability and safety is very important. This Schoodle is like a Satire to emphasize the responsibility of electronic manufacturing and engineering.