Electronic code generating circuit for use in railroad signaling systems
US6592081B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 28, 2001 |
| Grant date | Jul 15, 2003 |
| Priority date | — |
| Expiry date | Feb 28, 2021 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB61L3/24
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An electronic code transmitter is disclosed for driving a number of code following relays of a railroad signaling system. The electronic code transmitter comprises a timing circuit and a driving circuit. The timing circuit generates, at a predetermined code rate, square wave pulses with an approximate 50/50 duty cycle. The driving circuit receives the square wave pulses and conducts, at the predetermined code rate, a power source to the code following relays. Where the timing circuit is a timer IC operating in an astable oscillator mode, the timer IC receives an isolated DC power from a DC-DC converter. A resistor is coupled in parallel with the code following relays if the code following relays present a sufficiently high impedance load to the electronic code transmitter. Thereby, the electronic code transmitter is capable to drive code following relays of any load impedance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.