Abstract: Certain configurations of the present disclosure present a PTC starter. The PTC starter includes a housing, a first conductive terminal (6), a second conductive terminal (7), a control PTC thermistor (3), a start PTC thermistor (4) and a TRIAC (5), wherein the control PTC thermistor (3), the start PTC thermistor (4) and the TRIAC (5) being accommodated in the housing, the start PTC thermistor (4) being connected in series with the TRIAC (5), wherein one electrode of the control PTC thermistor (3) is connected with the gate (G) of the TRIAC (5), the control PTC thermistor (3) is connected in series with the start PTC thermistor (4), the volume of the control PTC thermistor (3) is less than 30 mm3, and the distance between the control PTC thermistor (3) and the start PTC thermistor (4) is less than 5 mm.

Abstract: Certain configurations of the present disclosure present a PTC starter. The PTC starter includes a housing, a first conductive terminal (6), a second conductive terminal (7), a control PTC thermistor (3), a start PTC thermistor (4) and a TRIAC (5), wherein the control PTC thermistor (3), the start PTC thermistor (4) and the TRIAC (5) being accommodated in the housing, the start PTC thermistor (4) being connected in series with the TRIAC (5), wherein one electrode of the control PTC thermistor (3) is connected with the gate (G) of the TRIAC (5), the control PTC thermistor (3) is connected in series with the start PTC thermistor (4), the volume of the control PTC thermistor (3) is less than 30 mm3, and the distance between the control PTC thermistor (3) and the start PTC thermistor (4) is less than 5 mm.

Abstract: A low cost motor starter is shown having a PTC resistor 12 serially connected to a triac 14 and a bias resistor in turn adapted to be connected to the start winding of a single phase motor. A reed relay 16 having a sense coil 16a serially connected to the main winding in one preferred embodiment and in parallel with the main and start windings in a second preferred embodiment, is magnetically coupled to reed contacts 16b, 16c. Reed contact 16b is connected to a location intermediate the PTC resistor 12 and the triac 14 while reed contact 16c is connected to the gate of the triac. A gate signal phase shifting network comprising capacitor C1-R2 is also connected to reed contact 16c and the gate.

Abstract: A low cost motor starter is shown having a PTC resistor 12 serially connected to a triac 14 and a bias resistor in turn adapted to be connected to the start winding of a single phase motor. A reed relay 16 having a sense coil 16a serially connected to the main winding in one preferred embodiment and in parallel with the main and start windings in a second preferred embodiment, is magnetically coupled to reed contacts 16b, 16c. Reed contact 16b is connected to a location intermediate the PTC resistor 12 and the triac 14 while reed contact 16c is connected to the gate of the triac. A gate signal phase shifting network comprising capacitor C1-R2 is also connected to reed contact 16c and the gate.

Abstract: A solid state starting system for electric motors having main and auxiliary windings of the capacitor start induction run and capacitor start-capacitor run types uses a triac serially connected to the auxiliary winding. The system differentially measures the auxiliary winding voltage and provides a triac gate signal when in the START mode. When the auxiliary voltage reaches a calibratable cut-out voltage the triac is disabled until the auxiliary winding voltage decreases to a level below a calibratable cut-in voltage. The slope of the percent motor speed cut-out versus percent line voltage is calibratable to permit compensation for variations in line voltage. The triac can be directly driven or driven through an optically coupled interface having a triac output (OCI).

Abstract: A single phase, capacitor start electric motor is shown in which energization of the auxiliary winding is controlled by a triac. The triac is protected from excessive voltages caused by the vector sum of capacitor, line and induced voltages which can occur at turn-off of the triac. The triac is protected in several embodiments by a gated semiconductor switch serially connected to a current limiting or discharge resistor, both being coupled across the triac. The semiconductor switch has a voltage breakdown device connected in its gate circuit. When voltage across the triac exceeds a selected level the gated semiconductor is turned on thereby drawing sufficient current momentarily to limit the voltage across the triac to a safe level and allowing the capacitor to discharge its voltage through the auxiliary winding circuit. In another embodiment a stack of high voltage bilateral triggering devices is placed across the triac.

Abstract: A solid state starting system for electric motors having main and start windings of the capacitor start, capacitor start-capacitor run and split phase types uses a triac serially connected to the start winding. The system turns on the triac upon energization of the motor from an at rest condition and measures the locked rotor value of either the main winding current for any of the above motor types or start winding voltage for the capacitor start, capacitor start-capacitor run motor types. The system stores that valve as a calibration value and then measures subsequent values and turns off the triac when the subsequent values reach a selected proportion of the calibration value. The system re-energizes the triac upon further subsequent measured values reaching a selected cut in value relative to the calibration value which is indicative of an overload or stall condition. The calibration value is retained for a given period of time following a loss of power to provide desired starting characteristics.