Electronic delay circuit for firing ignition element
US5363765A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1993 |
| Grant date | Nov 15, 1994 |
| Priority date | — |
| Expiry date | Mar 15, 2013 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF42D1/055
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An electronic delay circuit for firing an ignition element. The delay circuit includes a capacitor which stores electric energy supplied from an electric blasting machine, an oscillator generating a clock pulse train, a circuit for over-exciting the oscillator, a counter which counts clock pulses of the clock pulse train, and a circuit for maintaining a reset state of the counter for a predetermined time period after the electric energy is supplied. The counter produces a trigger signal when it counts a predetermined number of the clock pulses, and the electric energy stored in the capacitor is discharged to the ignition element. Since the oscillator enters into the steady state in a very short time by the over-excitation, the delay circuit has large resistance to external noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.