Turbo Chef Technologies NGC-1007 service manual Microwave System

26 THE MICROWAVE SYSTEM

TRANSFORMER OUTPUT VOLTAGE

+(B)

+2400 V

0

(A)

-2400 V

-(C)

2400

VDC

+ + -

2400 Current

Flow

-

CAPACITOR CHARGES

ON POSITIVE VOLTAGE SWING

F I G U R E 19: Voltage Doubler Circuit Theory of Operation

MAGNETRON VOLTAGE

+(B)

0

(A)

	-(C)	-4800 V
	2400
	VDC
-	+ -
2400	Current	4800
		VDC
	Flow
+

CHARGED CAPACITOR PLUS TRANSFORMER

ON NEGATIVE VOLTAGE SWING

VOLTAGE DOUBLER THEORY OF OPERATION

Figure 19

1.The high-voltage transformer steps up the input voltage to approximately 2400 volts peak (4800 volts peak to peak).

2.The high-voltage capacitor charges to 2400 volts on the positive going voltage via the high volt- age diode’s conduction.

3.The high-voltage transformer plus the charged high-voltage capacitor supply down to -4800 volts to the magnetron when the voltage goes negative. (high-voltage diode is back biased.)

4.The magnetron converts negative input voltage (and current) to RF energy at 2450 MHz.

W A R N I N G : Do not attempt to measure these voltages.

MICROWAVE SYSTEM PARTS

Figures 20 and 21

11.NGC-3062-1 HV Transformer (2 per oven, 1 per kit) - USA, Mexico, Brazil, S. Korea

NGC-3062-2 HV Transformer (2 per oven, 1 per kit) - Europe, Asia, Pacific, Australia, UK, Ireland

NGC-3062-3 HV Transformer (2 per oven, 1 per kit) - Japan

12.NGC-3020 High Voltage Capacitor (2 per oven, 1 per kit) - USA, Mexico, Brazil, S. Korea

NGC-3020-2 High Voltage Capacitor (2 per oven, 1 per kit) - Europe, Asia, Pacific, Australia, UK, Ireland, Japan 50 Hz

100207 High Voltage Capacitor (2 per oven, 1 per kit) - Japan 60 Hz