Delay type electric detonator
US4899658A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Oct 7, 1988 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Oct 7, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF42B3/122
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An electric detonator of the delay type including a housing having a metal portion and an insulating portion, a pair of leg wires extending outside through the housing, a delay circuit connected across the leg wires and generating an ignition current at a predetermined timing, and an igniting resistor connected to an output terminal of the delay circuit and one of the leg wires. In order to check the resistance value of the igniting resistor even after the detonator has been assembled, a by-pass resistor is connected between the other of the leg wires and a junction point between the delay circuit and the igniting resistor. A small measuring current is conducted through the igniting resistor via the by-pass resistor to generate a voltage drop across the igniting resistor. This voltage drop is measured by connecting a voltage measuring device between the leg wire and the metal portion of the housing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.