Free Simple Circuit Diagram
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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This is a voltmeter circuit that use FET as the buffer to improve the input impedance. This circuit uses A2N3819 FET which provides a solid-state VOM. Beside that, a cathode follower in a VOM of this circuit is The 2N3819. The calibration of this circuit is done by adjusting R12 (scale/sensitivity) and R14 (zero offset). Since FET has very high […]
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This is a circuit of Low-Light Level Drop Detector. This circuit utilize self-biasing configuration to detect small changes in light level. This circuit usually used in monitoring very low droplets rates. The collector of the transistor gives feedback that is used to stabilize the bias of the photodarlington. The effect on optical performance is reduced by a high base-source impedance […]
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