beautypg.com

Microwave circuit – TurboChef Technologies C3/CMulti User Manual

Page 88

background image


Microwave Circuit

9-6

Magnetron High Voltage Transformer (102093)

The magnetron transformer is a ferro-resonant
design which limits fault currents and minimizes

magnetron power changes due to input voltage
changes.

An

automatic

resetting

over-

temperature switch is embedded in the high
voltage secondary winding and removes power
form the primary winding if an over-temperature
condition occurs.

In the C3 SERIES a separate transformer is used
to preheat the filament for the magnetron for
better

operation.

+(B)

0

-(C)

HV TRANSFORMER

OUTPUT VOLTAGE

MAGNETRON VOLTAGE

Current

Flow

2400

+

-

+

-

2400

VDC

Current

Flow

+

-

-

+

2400

2400

VDC

4800

VDC

+(B)

(A)

-

(C)

- 4800 V

CAPACITOR CHARGES ON

POSITIVE VOLTAGE SWING

CHARGED CAPACITOR PLUS TRANSFORMER

ON NEGATIVE VOLTAGE SWING

+2400 V

-2400 V

(A)

0

1. The Magnetron 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 Voltage Diode’s forward conduction.

3. The Magnetron Transformer plus the charged High Voltage supply up to - 4800 volts to the

Magnetron on the negative going voltage (High Voltage Diode is back biased).

4. The Magnetron converts the negative input voltage (and Current) to RF energy at 2450

MHz with approximately 60% efficiency.

WARNING: DO NOT ATTEMPT TO MEASURE THESE VOLTAGES

FIGURE 9 - 2 Magnetron High Voltage Power Supply


This manual is related to the following products: