13Ap1:10 Tachometer Input - ESAB Origo Feed 304 M12 Series Service Manual

DESCRIPTION OF OPERATION
Breaking
When the motor starts, capacitor C60 charges up to 15 V, with zener diodes D20 and D43
limiting the voltage across it. Braking is activated by the optocoupler IC3. When the transistor
in IC3 is turned on by the LED, 15 V from capacitor C60 is connected to the gate of transistor
Qb. Transistor Qb turns on and short circuits the motor through the resistors R85 – R87. The
resistors limit the braking current to about 20 A.

13AP1:10 Tachometer input

Feed 304: valid for serial numbers 238-xxx-xxxx, 410-xxx-xxxx, 440-xxx-xxxx, 502-xxx-xxxx
and 620-xxx-xxxx.
Feed 484: valid for all serial numbers.
The tachometer 13G1 is fitted inside the motor casing. Comparator IC5 / IC14 converts the
sine wave signal from the tachogenerator to a square wave at the same frequency.
Feed 304: At a wire feed speed of 25 m/min, it produces a signal frequency of 667 Hz.
Feed 484: At a wire feed speed of 25 m/min, it produces a signal frequency of 814 Hz.
Pulse generator input
Valid for Feed 304 from serial number 917-xxx-xxxx.
The pulse generator (encoder), 13G1, is fitted to drive motor 13M1. It generates 60 pulses
per revolution.
At a wire feed speed of 25 m/min, the pulse generator produces a pulse frequency of
10230 Hz.
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