Archive for the ‘Control and Monitoring’ Category
Single-Cell Voltage Monitor

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 …[Read More]
Remote Sensor System Pre-Amp

Remote sensor might cause a trouble if it’s a passive type, has very low power output, and should be connected with relatively long cables. By supplying a current or voltage source through its connection wire, it’s possible to make long enough wiring without suffering much noise/interference. The following schematic diagram show a circuit consist of …[Read More]

In furnace operation, it is necessary to make sure that the fuel or gas is ignited properly by detecting the flame. If there’s no flame detected, the situation can be dangerous if the furnace is flooded with explosive gas, so the fuel/gas supply valve should be closed automatically to avoid catastrophic disaster. A thermocouple can …[Read More]
Over/Under Voltage Monitor

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 …[Read More]
Infinite Resolution Frequency Multiplier/Divider

Normally, frequency multiplier or divider has only discrete ratio operation since it uses digital divider as the main process for division or multiplication. By first converting the incoming frequency into a proportional DC voltage, we can perform frequency scaling easily with no restriction of discrete ratio operation. Here is the block diagram the scheme: We …[Read More]
Pulse Delay Generator

This circuit is a Delayed Pulse Generator that is used to provide pulse rate and independent control of initial delay. The pulse generator of this circuit is IC1c which the operation is depended on the normally low O/P of the IC1a. The PB1 is used to make the circuit input goes low. When PB1 is …[Read More]
Analog Signal Transmission Through DC Supply Line

If the sensor system need an active supply, we can use only a single pair of cable to carry both the power supply and the output signal. Not only simplify the wiring, converting analog voltage level to frequency modulated pulse improve the noise immunity as well. Here is the schematic diagram of the system: The …[Read More]
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