RU95101778A - Thyristor regulator of electroheater temperature - Google Patents

Abstract

FIELD: electroheaters temperature regulators operated by alternating electrical current and using thyristors, thermal resistors and electronic means of control. SUBSTANCE: aim is to provide high accuracy of adjustment, stability, reliability and economical efficiency of regulator, to increase its service life and to decrease dimensions. Aim is realized by usage for control of balanced bridge with thermal resistor in one of arms and with zero-indicator acting on thyristor control - in diagonal. Thyristor is in series with electrical heater connected to alternating current network feeding bridge circuit. The circuit provides optimal time delay of starting pulses in respect to beginning of network working half-cycles. Thyristor triggering is exercised at instant of time, as anode voltage is already present in thyristor and it is sufficient for thyristor triggering and is close to minimum value as du/dt, di/dt and commutation interferences are minimal. EFFECT: high accuracy of adjustment, high stability, reliability and economical efficiency of regulator.

Claims (1)

The invention relates to temperature controllers for electric heaters operating on alternating current and using thyristors, thermistors and electronic controls. The purpose of the invention is the provision of high accuracy regulation, stability, reliability and efficiency of the regulator, increasing its service life and reducing size. This is achieved by using a balanced bridge with a thermistor in one of the shoulders and a null indicator affecting the thyristor control in the diagonal to control the temperature. The thyristor is connected in series with the electric heater to an alternating current network supplying the bridge circuit. The circuit provides the optimal delay time of the triggering pulses relative to the beginning of the working half-periods of the network. The thyristors are started at times when an anode voltage is already present on the thyristor, sufficient to turn it on, but close to the minimum, when du / dt, di / dt and switching noise are minimal.