Free Circuit Diagram

This is a circuit of board system monitoring for temperature and voltage condition. It uses the NE1617A. The NE1617A is a 2 channel temperature sensor. It can measure remote and internal sensor. It also supports up to nine devices per bus. The temperature data update is selectable from 125 ms to 16 seconds, if it [...]

This is a circuit that transmits temperature data over an IR link and it allows the isolation of temperature sensor. It is a good solution of obtaining temperature readings from points at potentials a few tens of volts from ground by linking a temperature probe  only by an IR connection to the readout point. This [...]

There are some digital and analog that can be used for compensating a PT100 RTD nonlinearity. We can implemented the digital linearization by implementing the previous generic equation  or by a lookup table. By implementing the previous generic equation we can calculate temperature values directly, based on the actual measured RTD resistance. A lookup table [...]

In some temperature-sensing applications there are some problems caused by the placement of sensors on location where the potential is very different from that of the data-acquisition-system common. So the operating temperature sensor must be isolated from its data-acquisition system galvanically.  And the power’s source for the sensor was isolated. This circuit is designed to [...]

The temperature of a quartz crystal for oscillator should to be kept constant to operate at very stable frequency. This oven temperature controller is suitable for such purpose.  Here is the schematic diagram of the temperature control circuit:

Although this circuit is small and simple, the design use a PWM output to preserve the efficiency.  The [...]

LM56 is a monolithic  thermostat designed for simple temperature control. The chip has two programmable threshold that can be used to drive a fan and or alarm.  Here is the schematic diagram of the fan control circuit:

The circuit will turn on the fan when the temperature rise above 50 Celsius degree, and this threshold is [...]