Schematic Diagrams

Useful schematic and wiring diagrams. ✔ ✔ Enjoy electronic circuits, let your idea comes to hardware

battery tester

Variable High Power “Resistor” For Power Supply Testing

Current handling capability of a power supply system often needed to be checked. Finding high power rated variable resistor to provide variable load testing might be difficult. There is wire wound type but it’s not always available at your local store, and the price and performance might be disappointing. This variable high power “resistor” uses […]

Battery Level Indicator

A battery level indicator circuit is depicted in the schematic diagram below. This circuit is designed for 9V battery operation, as this circuit will start dimming below 7V and will be completely turned off at 6V.  If you want the LED indicator not to dimming but just abruptly turns off at below 6V, then you […]


Low Power Under- and Over-Voltage Monitor

This voltage monitor has two  threshold, VTH for undervoltage and VTH’ for overvoltage. Using the component values shown in the schematic diagram below, this circuit give 6V for VTH and 15V for VTH1. Above 6V, the LED indicator of this voltage monitor  circuit will increase the flash rate until reach 15V.  This circuit will stop […]


LM10 Battery Voltage Threshold Indicator

A battery threshold indicator circuit shown in the schematic diagram below has current regulation mechanism in driving the LED. A sufficient current should be satisfied at the minimum voltage but no excessive current when the voltage is at the highest level. Balance pin (5) is used as the reference  voltage for regulating the current. This […]

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1.5V to 9V Battery Tester

Here the circuit diagram of DC battery tester designed by Matthew B.. This circuit can be used to measure DC battery from 1.5V up to 9V. Component Parts List: R1 = 18K Ohm R2 = 240 Ohm R3 = 8.2K Ohm R4 = 3K Ohm R5 = 10 Ohm M1 = Panel Meter (Anyone will […]

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