Automotive electrical network voltage regulation monitoring circuit

US4374380A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Ulrich Giepen · Mundelsheim, DE
• Friedhelm Meyer · Mühlacker, DE

Key dates

• Filing date: Dec 4, 1979
• Grant date: Feb 15, 1983
• Expiry date: Dec 4, 1999

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02J7/16
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

To provide a visible output indication, for example by an indicator light on a controller supervisory panel of the vehicle, of proper functioning of the voltage regulator power transistor, monitoring circuits are provided which sense the electrical condition of current flow through or the voltage condition of the field winding or output bus respectively by including a light emitting diode (LED) in an indicator circuit, for example by connecting it in series to the coupling resistor. In one form, a Zener diode Z (FIG. 1) is connected across the output bus with the LED in series, so that the LED will light if the output bus reaches a voltage which might damage the battery, for example due to short circuit or alloying-through of the output transistor T of the voltage regulator; in another form, an LED which preferably is green, LDg (FIG. 2), is connected across the output transistor, the green LED lighting if the output transistor functions properly, but extinguishing if the output transistor alloys-through; the LED with the Zener diode and the green LED can be provided together to form alternate outputs--green indicating proper operation and red already danger; in another form, an LE…