Electric heating – Heating devices – With power supply and voltage or current regulation or...
Patent
1974-12-06
1976-03-09
Envall, Jr., R. N.
Electric heating
Heating devices
With power supply and voltage or current regulation or...
219494, 219497, 219501, H05B 102
Patent
active
039433315
ABSTRACT:
A temperature control circuit is disclosed for controlling the firing angle of a thyristor such as a silicon controlled rectifier connected in series with a heater across an alternating power source. The control circuit comprises a field effect transistor having its source and drain electrodes connected for firing of the rectifier when the field effect transistor is rendered conductive, and a bias phase control connected to the gate of the field effect transistor for generating a fixed A.C. voltage component which is phase shifted by about 90.degree. with respect to the voltage of the power source together with a temperature dependent D.C. voltage component to control the firing angle of the silicon controlled rectifier in accordance with the heat generated by the heater, the sum of the A.C. and D.C. voltage components being fed to the gate of the field effect transistor. The temperature dependent D.C. voltage is generated by a circuit comprising a parallel arrangement including an adjustable resistor connected in series with a first diode and a temperature sensitive resistor connected in series with an oppositely poled second diode, each of such diodes being poled so as to produce a more negative D.C. voltage component with increasing temperature and vice-versa.
REFERENCES:
patent: 3553429 (1971-01-01), Nelson
patent: 3678247 (1972-07-01), Sawa et al.
patent: 3854033 (1974-12-01), Edge
Bell Fred E.
Envall, Jr. R. N.
Multi-State Devices Ltd.
LandOfFree
Temperature control circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Temperature control circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Temperature control circuit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-834377