| |
G8MNY > TECH 16.07.03 00:35l 24 Lines 991 Bytes #999 (0) @ WW
BID : 5755_GB7CIP
Read: DF5NK DB0FHN GUEST OE7FMI
Subj: 12V System Surge protection
Path: DB0FHN<DB0RGB<OK0PPL<RZ6HXA<HA3PG<IK1ZNW<GB7CRV<GB7CIP
Sent: 030715/0706Z @:GB7CIP.#32.GBR.EU #:5755 [Caterham] $:5755_GB7CIP
From: G8MNY@GB7CIP.#32.GBR.EU
To : TECH@WW
On 24cms ATV repeater GB3HV, we used the high current diode protectors from RS,
part No RS 239-494 which is actually a special 15V zener diode, designed to
always blow S/C when overpowered, it can handle pulse currents of 75A. This was
used even thought we had a 30AH car battery connected as well, we were worried
about lightening spikes to the site.
When our low voltage chopper PSU blew up some years ago, it put it's 60V DC
rail out to the battery, blowing the series 30A bolted in fuse, & applying 60V
to all the 12V kit. The spike zeners did their job & blew all the individual
unit fuses. Only the odd unprotected control transistor got zapped.
This protection certainly saved 300 pounds of expensive 23cm silicon from
burning out!
A differnt design SMPSU is now in use with extra fuses so that there is a fuse
between the PSU-Batt fuse, a another fuse battery to load wiring, & individual
unit fuses.
/QSL
73 De John, G8MNY @ GB7CIP
Read previous mail | Read next mail
| |
