Free electronic circuit design and schematic diagram
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 pin generate 23 mV, which […]
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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 flashing at voltage below 6V […]
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A meter amplifier can be designed using LM10 integrated circuit (IC). The accuracy of full-scale sensitivity is good for over 15°C to 155°C at 10mV and 100nA. Here is the schematic diagram of the circuit: R5 is used to correct the offset voltage error, while R4 is used to balance the bias current. The zero calibration uses the reference voltage […]
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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 can remove R3, and change […]
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Monitoring battery voltage can be important in some application. Some battery monitor will be simply a continuous LED lamp which is dimming according to the voltage level. Here is presented monitoring circuit that flashing, which is more noticeable than simple dimming the light intensity. At 1.2V, the LED begin flashing, and the flashing rate will increase as the voltage increase. […]
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This is a over/under voltage monitor circuit. This circuit is used to monitor Any potential from 1 to 15 V. If there is a undesirable variation was occurs, two lamps will flash. The voltage differential fro lamp turn off and turn off is about 0.2V at any setting. Low and high set points are independent of each other. The type […]
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Below is two single ended circuits which connected back to back give differential input. This circuit is not only has differential input feature, but also high impedance, much higher compared with the analog ammeter without this circuit. Here is the schematic diagram of the circuit: [Circuit’s schematic diagram source: seekic.com]
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