Digital meter using calculator components
US4492916A · kind A · utility
Inventor
Key dates
| Filing date | Sep 21, 1981 |
| Grant date | Jan 8, 1985 |
| Priority date | — |
| Expiry date | Sep 21, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/50
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention uses an RC circuit 12 to convert an analog quantity to be measured into a time interval proportional to the measured quantity by using a resistive element in the RC circuit responsive to the quantity being measured. The RC circuit starts and stops a time base generator 13 to produce pulses having a total number proportional to the time interval, and a gate system 14 applies the pulses to the key terminals of the circuitry 16 of a pocket calculator 10 for indicating the pulse count on a display 15, either directly or after being processed by functions available in the calculator circuitry. The RC circuit can also be used to start and stop a time base generator 33 built into a digital stopwatch for displaying a pulse count proportional to the quantity measured. The measured quantity can be a capacitance value, a resistance value, or energy impinging on a responsive transducer in the RC circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.