|Author ||Message |
|eric || |
|Posted: Thu Oct 05, 2006 11:55 pm Post subject: Mains/fuse failure indicator || |
| Site Admin Joined: 01 Jan 1970 Posts: 311 || |
|G. Kleine 062
The indicator shows when the mains is present at its output by a
continuous glow of a neon bulb, La1, and when the fuse is blown by
flashing of the neon bulb.
When the fuse is intact, capacitor C2 acts as the series resistance
for the neon bulb, so that this glows continuously. When the
fuse has blow, the mains voltage across diode D1 is applied as a
pulsating direct voltage to network R1-C1. Capacitor C1 charges
slowly and when the voltage across it reaches 80–100 V, the neon
bulb comes on. Capacitor C1 is then discharged slowly via diode
D2 and the bulb. When the voltage across it has dropped sufficiently,
the bulb goes out, whereupon C1 slowly charges again. This
process repeats itself, so that, provided the values of R1 and C1 are
right, the bulb flashes visibly.
The potential across capacitor C2 is a ramp with a peak value
of 30 V (which is, of course, applied to the load).
Note that the neon bulb used for this purpose must not be a
type that has a built-in series resistor.
|Back to top || |
All times are GMT
| Current Source with Indicator
| Electronic Fuse — protection ‘deluxe’
| Mains Remote Transmitter
Audio power, headphone and pre Amplifier, Digital audio circuits, Loudspeakers projects
PLC articles, examples, hardware, hints and tips, software
Powered by phpBB // Template by Mike Lothar