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berkeman said:Potentiometers have a minimum wiper current that is required to keep that interface clean and low-resistance. If you connect a pot as shown in the schematic, with the wiper only connecting to the input of an opamp (especially if it is a CMOS opamp with very low input bias current), then over time the wiper contact will become unreliable. If the wiper is adjusted daily or something, then it is less of an issue. But in a circuit like this one, where you set the threshold once and leave it there for years, the operation of the circuit is likely to fail eventually.
Yes. One variation that works well is to put the pot in series with another resistor to ground. Tie the wiper of the pot to the midpoint between the pot and the resistor, and also tie that midpoint into the opamp input. The midpoint tie should be the CCW end of the pot in this application, so that when you turn the pot control clockwise, that shorts out more and more of the pot, and raises the setpoint going into the opamp.triden said:What would you normally do to prevent that? Just load it a bit with a resistor or something?
A low voltage indicator circuit is a circuit designed to monitor and display the voltage level of a power source. It is commonly used in electronic devices to indicate when the battery or power supply is running low.
A low voltage indicator circuit typically consists of a voltage comparator, a reference voltage, and a display such as an LED. The comparator compares the input voltage from the power source to the reference voltage and triggers the LED to light up when the input voltage drops below the reference voltage.
The components needed for a low voltage indicator circuit may vary, but typically include a voltage regulator, a voltage comparator, a reference voltage source, a display such as an LED, and necessary resistors and capacitors.
Yes, a low voltage indicator circuit can be adjusted for different voltage levels by changing the reference voltage or using a voltage divider circuit to adjust the input voltage range for the comparator.
Low voltage indicator circuits are commonly used in electronic devices such as portable chargers, power banks, and battery-operated devices to inform the user when the battery or power supply is running low. They can also be used in automotive and industrial applications to monitor the voltage level of batteries or power sources.