Voltage regulator for a generator

• US 4,237,412 A
• Filed: 03/02/1978
• Issued: 12/02/1980
• Est. Priority Date: 03/09/1977
• Status: Expired due to Term

• Current Assignee: AB Volvo
• Original Assignee: AB Volvo
• Inventors: Rundlof, Lars N.
• Primary Examiner(s): Hickey, Robert J.
• Application Number:
  US05/882,897
• Time in Patent Office: 1,006 Days
• Field of Search: 322/28, 322/33, 322/34, 320/35, 320/36, 320/64, 320/68
• US Class Current: 322/28
• CPC Class Codes: H02J 7/007192 in response to temperature
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle

Abstract

A voltage regulator intended for a car generator in order to give an appropriate charging voltage which can be compensated for variations in ambient temperature or the like. An advantage of the present regulator is that it may be used with or without an external regulator element, the switching-in of this external element being compensated by the automatic switching-in of a balancing resistor.

Claims

1. A voltage regulator for a generator of the type used in motor vehicles, the regulator being adapted to set, in use, the generator at a charging voltage when charging a storage battery, the regulator comprising a voltage divider (R₄, R₅) having a pair of branches for sensing the voltage of a generator (G) and comparing such voltage with a reference voltage (Z);

switch means (T₁);

an additional voltage divider element (R₁) connected in one branch (R₅) of the first-mentioned voltage divider (R₄, R₅) through said switch means (T₁) and only when said switch means (T₁) is rendered operative;

terminal means (T) for connecting a regulator element (R_T) in the other branch (R₄) of said first-mentioned voltage divider (R₄, R₅); and

means (R₂, R₃) for rendering operative said switch means (T₁) to connect said additional voltage divider element (R₁) in said one branch (R₅) of the voltage divider, only when a said regulator element (R_T) is connected to said terminal means (T).

2. A voltage regulator as claimed in claim 1, in which said switch means is a switch transistor (T₁) coupled in series with said additional voltage divider element (R₁), said means for rendering operative said switch means comprising a second voltage divider (R₂, R₃) coupled to said terminal means (T), and a diode (D₃) by which the terminal means (T) is connected to the first-mentioned voltage divider (R₄, R₅), said diode (D₃) being connected with regard to its polarity so that, when a said regulator element (R_T) is not connected to the terminal means (T), the diode (D₃) prevents current from the first-mentioned voltage divider (R₄, R₅) from reaching the second voltage divider (R₂, R₃) so that the switch transistor (T₁) remains inoperative.

3. A voltage divider as claimed in claim 1, in combination with a said regulator element (R_T) connected to said terminal means (T), the regulator element being a temperature-sensitive element adapted to be mounted next to a storage battery to adjust the generator voltage so that the generator voltage is adapted to the temperature of the storage battery.

4. A voltage regulator as claimed in claim 2, in combination with a said regulator element (R_T) connected to said terminal means (T), the regulator element being a temperature-sensitive element adapted to be mounted next to a storage battery to adjust the generator voltage so that the generator voltage is adapted to the temperature of the storage battery.