Pencell Charge Indicator circuit diagram test

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rajaram04

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Hello sir

Here i hv a circuit diagram for single 1.5 volts cell



with link

**broken link removed**


please check !

i guess a conflict between 7806 & 9v battery , but you can identify in a better way . . thanks
 

Looks OK to me. The regulator would stop working properly as soon as the battery started to discharge due to little overhead but the circuit should work without the regulator anyway. All it does is compare the battery voltage with the drop across the two diodes.

Brian.
 

One big problem is that it only works with batteries that normally supply 1V5
so it's use is restricted
 

The stupid circuit has an accurate voltage regulator but uses diodes as its voltage reference that change their voltage when the temperature changes.
So it is a thermometer, not a pencell battery tester.
When the temperature is cold then a brand new pencell might cause the red LED to light.
When the temperature is hot then a fairly dead pencell might cause the green LED to light.

The two diodes should be a trimpot to set an accurate reference voltage that does not change when the temperature changes.
 

It is GOOD that Raj asks for verification that a lousy circuit from his country does not work because the website with this circuit TESTED it and lied about it.

This battery tester might have been tested only at one temperature. But doesn't everybody know that the forward voltage of a diode changes when the temperature changes and the voltage from a voltage regulator IC does not?
 

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