Samsung CM1819 Circuit Descriptions

40

Samsung Electronics

9-2 Description of Operating Sequence

When the oven is set to power level of 100%, 70% or 50%

When the oven is operating under the power level of 100%, 70% or 50%, the coil of power relay 1 and 2 are
energized intermittently by ON and OFF cycle of 30 seconds in order to supply power source to the High
Voltage Transformer and thus to oscillate the magnetron.

When the oven is set to DEFROST power position

When the oven is set to DEFROST power position, the coil of power relay 1 and 2 is programmed to operate
not together but alternately. That means power relay 1 should not work when the power relay 2 does(or relay
2 should not work when the power relay 1 does). The power realy 1 is energized for 15 seconds and then
the power relay 2 is energized for 15 seconds in turn. One complete ON and OFF cycle time of the power
relay 1 and 2 is 30 seconds.

The relation between indications on the display window and the output power of the microwave oven is as
shown in figure below.

Wiring Diagram & Operating Sequence

CM1819 / CM1829 CM1419 / CM1429

c(d): 20% -> opt open - 7sec(8sec) 25% -> opt short - 9sec(6sec)

10% -> opt open - 4sec(11sec) 13% -> opt short - 5sec(10sec)

e: 15sec

Note: One second included as a time for starting the magnetron oscillation

41

Samsung Electronics

9-2 Description of Operating Sequence (continued)

Initial operating status of Power Relay when the START button is pressed.

Relays are designed to work as shown in the figure below.
When the oven is set to DEFROST power position, Inrush Relay1 and Power Relay1 are programmed to
work with Inrush Relay2 and Power Relay2 not simultaneously but alternately.

Wiring Diagram & Operating Sequence

Operating

Operating Time of Relays (100%, 70%, 50% power)

Sequence

NOTE :

LAMP: Lamp Relay (250V 5A)
MAIN: Main Relay (250V 16A)
VENT: Ventilation Motor Relay (250V 5A)
IR1: Inrush Relay1 (250V 5A)
IR2: Inrush Relay2 (250V 5A)
P1: Power Relay1 (250V 16A)
P2: Power Relay2 (250V 16A)