Andrew Leigh
Member
Hi,
I am finally calibrating my thermostat circuit but have noticed that at the point of switching that the relay "chatters", switching on and off repeatedly. I thought it had something to do with the hysteresis pot but this is not the case.
The one thing that was pointed out in a previous post was that I had no smoothing on the power supply. This will be corrected but currently this is the circuit with the transformer supplying directly through the bridge rectifyier which measures 12.2V d.c. at the output.
The three pots are for the Range which is the desired range one wants the unit to operate in. The other is the Temperature which is the desired temperature within the Range that one wishes and the last is the Hysteresis.
The thermistor measures out at about 11k when at the desired temperature of 4°C.
Could the dirty supply be responsible? Any thoughts?
Cheers
Andrew
I am finally calibrating my thermostat circuit but have noticed that at the point of switching that the relay "chatters", switching on and off repeatedly. I thought it had something to do with the hysteresis pot but this is not the case.
The one thing that was pointed out in a previous post was that I had no smoothing on the power supply. This will be corrected but currently this is the circuit with the transformer supplying directly through the bridge rectifyier which measures 12.2V d.c. at the output.
The three pots are for the Range which is the desired range one wants the unit to operate in. The other is the Temperature which is the desired temperature within the Range that one wishes and the last is the Hysteresis.
The thermistor measures out at about 11k when at the desired temperature of 4°C.
Could the dirty supply be responsible? Any thoughts?
Cheers
Andrew