Two-simple-temperature-to-time-converters

  
Both of these converters use CMOS inverters. Figure 105-1A shows a free-running circuit having both the pulse duration and pulse pause dependent on temperature of the diode D8. It can be used where a synchronization between the converter and something else is not required. Figure 105-lB shows a one shot circuit that produces a pulse with its duration dependent of temperature of diode D8. The additional diode D1 should have inverse current low enough to not influence the discharging process in the network rc when the INVA output is low.
Two-simple-temperature-to-time-converters - schematic

A silicon component or a GaAsP LED can be used. The converter is intended for a digital system producing a RADY pulse which disappears after the conversion process is ended. Where V0 is the sensor diode forward voltage and VDD is the supply voltage of the CMOS chip. Resistance R must be much higher than R8. A 0.1-I"F capacitor can be applied in parallel with D5, if necessary, to repulse stray pickup and noise in a long cable. The circuits described can be used with a temperature sensitive resistor instead of the diode D5.




Leave Comment

characters left:

New Circuits

.