Free Simple Circuit Diagram
A normal 9V battery would be considered as dead battery when the voltage falls below 7 Volts. With this switching regulator, a lifetime of a 9V battery will be extended by boosting the voltage if the battery voltage falls under 7.5V. This circuit will maintain the voltage at 7V until the battery voltage falls down to 2.2 volt, a point […]
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This is a remote on-off switch circuit. With this circuit, we can take the benefit of using small switch to control larger AC current from high power devices. Safer operation is the other benefit, since this circuit is control the power without running line-voltage switch leads, only low voltage exposure for human operator. Here is the schematic diagram of the […]
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When battery voltage drops to a certain level set by 10k pot, this simple battery monitor circuit energizes a LED. For reading battery voltage in 1 V steps or even steps as small as 0.1 V, we can add any number of additional circuits.This circuit provides LED indication for easy use on modern cars, replacing the ammeter reading which is […]
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A low-battery indicator circuit is shown in the schematic diagram. This battery indicator circuit will indicate the low battery condition by flashing the LED. This circuit utilize zener diodes as a voltage reference and 741 op amp as voltage comparator to detect if the voltage falls below a preset value. The op-amp will compare the voltage between two inputs, one […]
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