Star Tech Journal

STAR*TECH JOURNAL/JULY 1982
16
GO'l'l'LTEB
SYSTEM 80 SOLENOIDS
+24VDC
BACK EMF
+24VDC - - - - - -
+
--+
PULSE JUMPS CONTACTS
OR SHORTS TRANSISTOR
(MAY BE SEVERAL
THOUSAND VOLTS)
- v/
+
GROUND
GROUND
ENERGIZED
j
SWITCH OPENS
NO DIODE ON COIL
/
-
V
/.7VDC
GROUND
SWITCH OPENS
WITH DIODE ON COIL
GROUND
/
'
',, ____ _ ~,.:__ANODE
7
CATHODE
1N4004
1 AMP 400PIV
MINIMUM
RATING
---~--T
PROBLEMS:
ALL SOLENOIDS INOPERATIVE
1. +24VDC FUSE
2. +24VDC BRIDGE
3. Q ORT RELAY