Acceleration/deceleration control circuit for a stepping motor

• US 4,119,902 A
• Filed: 07/08/1977
• Issued: 10/10/1978
• Est. Priority Date: 07/08/1977
• Status: Expired due to Term

• Current Assignee: Mesur-Matic Electronics Corporation
• Original Assignee: Mesur-Matic Electronics Corporation
• Inventors: Newell, Harold R.
• Primary Examiner(s): Hohauser, Herman
• Application Number:
  US05/814,072
• Time in Patent Office: 459 Days
• Field of Search: 318/696, 318/685, 318/254, 318/138, 318/415, 328/44
• US Class Current: 318/696
• CPC Class Codes: G05B 19/416 characterised by control of velocity, acceleration or deceleration G05B19/19 takes precedence
• CPC Class Codes: H03K 5/00006 Changing the frequency modulating pulses H03K7/00; frequency dividers H03K21/00 - H03K29/00; additive or subtractive mixing of two pulse rates into one G06F7/605; pulse rate dividers G06F7/68
• CPC Class Codes: H03K 7/06 Frequency or rate modulation, i.e. PFM or PRM

Abstract

An acceleration/deceleration control circuit for a stepping motor includes a plural stage up/down counter connected to a source of pulses of constant repetition rate. The up/down counter output is connected to a decoder, such as a digital/analog converter, and conventionally, the output of the decoder is coupled to a variable rate oscillator, whose frequency increases, for example, as the output voltage of the digital/analog converter increases, and vice versa. The variable rate output is provided as an input to the stepping motor. In the improved arrangement a series RC circuit is coupled to the output of the decoder and the input of the variable rate oscillator is connected across the capacitor.

Claims

1. An improved acceleration control for a stepping motor which includes a source of pulses of constant frequency, a plural stage up/down counter with one input for stepping said counter is one direction connected to said source of pulses, decoding means connected to plural stage outputs of said counter for providing a voltage corresponding to a count stored in said counter, a variable frequency oscillator responsive to said voltage for providing pulses at a rate related to said voltage, said variable frequency oscillator having an output supplying pulses to said stepping motor, said output also connected to a further input of said plural stage up/down counter for stepping said counter in another direction wherein the improvement comprises integrating means connected between said decoder means and said variable frequency oscillator.

2. The apparatus of claim 1 wherein said integrating means comprises serially connected resistor and capacitor, with said variable frequency oscillator connected across said capacitor.

3. A pulse control circuit for smoothing pulse rate changes between an input line and an output line when said input line is subjected to discrete pulse groups each of which includes pulses at a fixed repetition rate, said control circuit comprising:

a plural stage up/down counter with said input line connected to an up counting input thereof,

a digital to analog converter connected to outputs of plural stages of said counter,

a series resistance-capacitance circuit connected to said digital to analog converter,

a variable repetition rate pulse source having a control input for controlling pulse repetition rate of output pulses produced thereby and connected to said capacitance,

said variable repetition rate pulse source having an output coupled to said output line and to a down count input of said counter.

4. The circuit of claim 3 in which said up/down counter has a zero count output,

said variable rate pulse source has a stop input, with said zero count output connected thereto.

5. The apparatus of claim 3 in which said variable rate pulse source has a disable input coupled to said input line.