Friday, October 24, 2014

Low Cost Universal Battery Charger Schematic

Low cost solution for charging of both NiCd and NiMh batteriesHere is the circuit diagram of a low cost universal charger for NiCD - NiMH batteries. This circuit is Ideal for car use. It has ability to transform a mains adapter in to a charger . This one can be used to charge cellular phone, toys, portables, video batteries, MP3 players, ... and [...]
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IC 555 Design Note

The popular Timer IC 555 is extensively used in short duration timing applications. IC 555 is a highly stable integrated circuit functioning as an accurate time delay generator and free running multivibrator. But one of the serious problem in 555 timer design is the false triggering of the circuit at power on or when voltage changes. The article [...]
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Solar Powered SLA Battery Maintenance

This circuit was designed to ‘baby-sit’ SLA (sealed lead-acid or ‘gel’) batteries using freely available solar power. SLA batteries suffer from relatively high internal energy loss which is not normally a problem until you go on holidays and disconnect them from their trickle current charger. In some cases, the absence of trickle charging current may [...]
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Ni Cd and Ni MH Adjustable constant current Circuit Diagram

This is a battery charger circuit with adjustable current for Ni-MH or Ni-Cd. It can be used for a constant current power, which can be set to any value from a few milliamps to about 500 mA. The maximum current is 500 mA, because that is the limit of transistor BC140. The input voltage must be above 5.25V output voltage, this is due to losses as 1.25V [...]
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Simple Water Level Indicator Circuit Schematic

The whole project was developed on a friends request. Its purpose was to remotely monitor the water-level in a metal tank located in the attic by means of a very simple control unit placed in the kitchen, some floors below.Mains requirements were:No separate supply for the remote circuit Main and remote units connected by a thin two-wire cable Simple [...]
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ESR Low Resistance Test Meter

As electrolytic capacitors age, their internal resistance, also known as "equivalent series resistance" (ESR), gradually increases. This can eventually lead to equipment failure. Using this design, you can measure the ESR of suspect capacitors as well as other small resistances. Basically, the circuit generates a low-voltage 100kHz test signal, which [...]
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Build a Voltage Regulator 12v to 24v using 7812

How to build a voltage regulator 12v to 24v using 7812. What many people do not know is it possible for a voltage regulator IC to provide an output voltage higher than its actual value. One method to achieve this is by connecting the "common" terminal to the middle point of a potential divider, but the problem with this method is that the regulators [...]
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