Output stage control circuit

• US 4,716,359 A
• Filed: 11/13/1986
• Issued: 12/29/1987
• Est. Priority Date: 11/15/1985
• Status: Expired due to Fees

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Kawata, Toshihiko, Numata, Hidetaka
• Primary Examiner(s): Wong, Peter S.
• Application Number:
  US06/930,794
• Time in Patent Office: 411 Days
• Field of Search: 323/267, 323/274-276, 323/279, 323/281, 323/349, 323/350, 323/222
• US Class Current: 323/349
• CPC Class Codes: F02D 2041/2058 using information of the actual current value
• CPC Class Codes: F02D 2041/2062 the current value is determined by simulation or estimation
• CPC Class Codes: F02D 2041/2075 Type of transistors or particular use thereof
• CPC Class Codes: F02D 41/20 Output circuits, e.g. for controlling currents in command coils
• CPC Class Codes: H03K 17/16 Modifications for eliminating interference voltages or currents
• CPC Class Codes: H03K 17/64 having inductive loads

Abstract

An output stage control circuit comprises an output driving means connected to a load for driving the same, a control means for taking out detection signals corresponding to signals flowing to the load and supplying analog control signals to the output driving means and a reference signal supply means for supplying reference signals to the control means, in which the analog control signals are generated depending on the detection signals and the reference signal, and the load is driven in an analogous manner by the output driving means depending on the analog control signals. The output stage control circuit can continuously supply the current to the load thereby operating the load stably with less occurrence of noises and stably for a long period of time.

Claims

1. An output stage control circuit for stably controlling a current through a varying load having one terminal connected to a power supply source, comprising:

output driving means constituted by an output stage transistor having its collector and emitter terminals connected in series between the other terminal of said load and ground for adjusting the current through said load;

control means constituted by a control transistor having its collector and emitter terminals connected between said other terminal of said load and a base terminal of said output stage transistor for supplying an analog control signal to said base terminal of said output stage transistor; and

a reference voltage supply source for providing a reference voltage signal to a base terminal of said control transistor,

whereby the current through the load is stably controlled by said output driving means in response to the analog control signal provided by said control means which is determined in response to the reference voltage signal.

2. An output stage control circuit as defined in claim 1, wherein the output driving means for driving the load is a bipolar transistor and the control means for supplying the analog control signals to said output driving means is a bipolar transistor.

3. An output stage control circuit as defined in claim 1, wherein the output driving means for driving the load is a field effect transistor and the control means for supplying analog control signals to said output driving means is a field effect transistor.