Frequency responsive circuit
US3956685A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 27, 1974 |
| Grant date | May 11, 1976 |
| Priority date | — |
| Expiry date | Nov 27, 1994 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02B1/04
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A capacitor of limited storage capacity is charged and discharged under control of a switching arrangement. The switching arrangement functions to connect the capacitor to a first steady current source of one polarity for a fixed first interval in each cycle of an input signal, and connects a second steady current source of opposite polarity to the capacitor for the remainder of the input signal cycle so that the voltage stored by the capacitor changes polarity when the frequency of the input signal traverses a threshold value. By shunting the capacitor with a fixed resistor, an output voltage linearly dependent on the input frequency can be obtained. By connecting the switching arrangement to connect the first current source to the capacitor for a fixed interval of time in each cycle of a first input signal, and to connect the second current source to the capacitor for a fixed interval of time in each cycle of a second input signal, a difference frequency discriminator function can be provided. Transistorized current sources and switching circuits, operated under control of a monostable multivibrator are described. The circuit may be used to control a change in the gas-air mixture…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.