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US 3,943,424 AGranted
Biasing system for SCR regulator
AssigneeMotorola, Inc.
InventorMelvin Arthur Lace
Life of this patent
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Abstract
Apparatus for switching a silicon controlled rectifier (SCR) into an off state and maintaining it there is disclosed. The apparatus uses a diode and an inductor in series with the cathode of the SCR. The voltage developed across the diode is negatively applied across the gate to cathode electrodes to maintain the SCR in an off condition. The diode voltage is applied to the SCR electrodes by a switching transistor. An alternator regulator system which uses the SCR control apparatus is also disclosed.
Claims26
A control system for an SCR regulator including;
- voltage supply means,
- an SCR connected for regulating the SCR through current supplied by the voltage supply means and having a gate, an anode, and a cathode electrode,
- a switching device having a control terminal, a first terminal and a second terminal, the first and second terminals having voltages applied therebetween and being substantially isolated from each other until a control signal exceeding a predetemined level is present at the control terminal whereupon the first and second terminals are substantially shorted together,
- wherein the improvement comprises:
- a series coupled device and inductor being energized by the SCR cathode through current flowing first through the device and subsequently through the inductor, the series device exhibiting a voltage drop due to the SCR through current,
- the first and second terminals of the switching device being coupled to the gate of the SCR and the junction between the series device and inductor respectively, and
- shunting means coupled across the series coupled device and inductor for shunting transient voltages created by the inductor,
- whereby during the period when the control signal is applied to the switching device the series device provides a negative bias between the gate and cathode of the SCR for keeping the SCR in a non-conductive state.
5 more elements
An Alternator-Regulator system comprising:
- generator means including an output winding having a first and a second terminal and a field coil winding having a first and a second terminal;
- voltage supply means;
- rectification means for coupling said output winding to said supply means for charging said supply means for the voltage generated in said output winding;
- voltage sensing means for monitoring the supply voltage and generating a control signal;
- and
- regulation means for energizing said field coil in response to said control signal including, a switching device having a control terminal for receiving said control signal and a first and a second terminal having voltages applied therebetween and being substantially isolated from each other until said control signal exceeds a predetermined level whereupon said first and second terminals are substantially shorted together, and SCR having its gate connected to said first switching termminal and coupled to a source of bias potential, a series device coupled in series with said field coil at said first field coil terminal and both being energized by the SCR cathode through current being coupled first through said series device and subsequently through said field coil, said series device exhibiting a voltage drop due to the SCR through current, said second switching terminal being coupled to the junction between said series device terminal and said field coil, shunting means coupled across the series coupled device and said field coil for shunting transient voltages created by said field coil, and a field coil exciting potential being applied between the anode of said SCR and said second field coil terminal.
3 more elements
An Alternator-Regulator system comprising:
- generator means including an output winding having a first and a second terminal and a field coil winding having a first and a second terminal;
- voltage supply means;
- rectification means for coupling said output winding to said supply means for charging said supply means from the voltage generated in said output winding;
- voltage sensing means for monitoring the supply voltage and generating a control signal;
- and
- regulation means for energizing said field coil in response to said control signal including, a switching device having a control terminal for receiving said control signal and a first and a second terminal having voltages applied therebetween and being substantially isolated from each other until said control signal exceeds a predetermined level whereupon said first and second terminals are substantially shorted, said second switching terminal being connected to said first field coil terminal, an SCR having its gate connected to said first switching terminal and coupled to a source of bias potential, a first diode having its anode connected to the cathode of a second diode and the cathode of said SCR, said first diode having its cathode coupled to said first field coil terminal, said second diode having its anode coupled to said second field coil terminal, and a field coil exciting potential coupled between the anode of said SCR and said second field coil terminal.
3 more elements
Dependencies are inferred from the claim text.