Microwave Pcb Control - Thermador CM301B Service Manual

CM Oven Service Manual

MICROWAVE PCB CONTROL

Refer to Page 12 to access the microwave PCB
control. The control has a relay (K1), two head-
ers (P1 & P3), and two 1/4˝ wire terminals
(P2-1 & P2-2). These components perform the
following functions:
Relay K1: Transfers 120-volts AC to the high-
voltage transformer to activate the microwave
circuitry. K1 is activated by 24-volts DC from
the relay board.
Header P1: Receives 24-volts and 5-volts DC
from the relay board using wire harness con-
nector P6. The 18-volts DC activates the relay
coil, and the 6-volts DC activates the triac on
the Microwave PCB Control.
Terminal P2-1: Inputs 120-volts AC from the
latch interlock switches.
Terminal P2-2: Outputs 120-volts AC to the
high-voltage transformer when relay K1 closes.
Header P3: Receives 12-volts AC from the
halogen light transformer at pins 1 & 2, and
Pins 3 & 4 output 12-volts DC to activate the
upper (or single) oven latch motor. The 12-
volts DC is produced by passing the 12-volts
AC through a bridge rectifier (see the follow-
ing circuits).
Positive AC Cycle
Negative AC Cycle
Header P1
Relay K1
Terminal P2-2
Terminal P2-1
Bridge
Rectifier Diodes
Header P3
Page 60
(+)
12 Volts AC
(–)
(–)
12 Volts AC
(+)
Lit. No. 94-30-006B
12 Volts
Pulsating DC
12 Volts
Pulsating DC