Voltage to duty cycle converter
US4390796A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1981 |
| Grant date | Jun 28, 1983 |
| Priority date | — |
| Expiry date | Apr 15, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K7/08
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An analog voltage to duty cycle converter is provided using a series connected resistor and capacitor. The capacitor is charged in one direction through the resistor from the difference between the analog voltage and a reference voltage maintained across a zener diode by one polarity of output from a differential amplifier responding to the charge across the capacitor. When the charge across the capacitor reaches the difference necessary to cause the differential amplifier to change the polarity of its output, a positive feedback firmly toggles the output to the other polarity and the capacitor is allowed to charge in the opposite direction due to cut-off of the zener current by a diode in the amplifier output circuit. The capacitor then charges in an opposite direction due to the analog voltage alone and the reference voltage again switches "on" when the amplifier output goes positive. The duty cycle is then proportional to the analog voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.