K2 POWER SUPPLY TEST PROCEDURE

Introduction

The Korad K2 power supply is designed for use with the K2, K1500 and 10KV K1 laser systems. The function of the power supply is to charge the energy storage capacitor to a selected voltage. The unit contains a high voltage supply, a voltage sensor and a low voltage interlock power supply.

Specifications

Input
Power 115 VAC
Line 50-60 cps,
Average Current 25 Amps

Controls

DUMP - Push Button S3 turns off the charging system and allows the dump solenoid to fall.
CHARGE - Push Button S2 causes the power supply to charge the capacitor bank to the selected voltage.
FIRE - Push Button S1 lights up when the bank has reached the ready condition. Depressing the push button starts the lamp discharge process.
KILOVOLTS - Potentiometer R(1), selects the charging voltage to the capacitor bank.
J2 - is a remote connector which makes it possible to operate the supply from a distance.
J3 & J4 - are connectors provided for the capacitor banks.

Equipment needed for checkout

Voltmeter (Simpson 260 or equivalent
Electrostatic Voltmeter
100uf 10KV capacitor
DC hypot (0-10 KV)

Checkout procedures

Checkout of the low voltage power supply.

Install the 1 Amp. fuse, BUT REMOVE THE 30 AMP. FUSE
Place a jumper across pin 1 and 2 on TB1
Turn supply on
Using the voltmeter, measure 34V ± 10% DC across filter capacitor C1
Using the voltmeter, measure 25VDC ± 5% on the logic board at CR5 in respect to ground. Depress the charge button, then the dump button. This voltage should not change.
Using the voltmeter, measure approximately 320VDC on TB1-10

Checkout of the logic board

When R(1) (kilovolt potentiometer) is at its extreme counter clock wise position the fire light should be on. Verify that fire light comes on.
Set the digidial to 2 KV. Verify fire light goes out and dump light comes on.
Depress charge button and verify that charge light comes on and dump light goes out. (Dump solenoid should also lift but system will not charge.)
Depress dump button and verify charge light goes out and dump light comes on.

Checkout of HV supply

Connect a negative DC hypot to J6
Set the digidial to 2 KV
Depress the charge button
Turn the hypot on and bring the voltage up slowly to 2 KV. verify that the power supply fire light comes on when the hypot reaches approximately 2 KV, The meter on the supply should read about 2 KV also.
Repeat above step at 8 KV

To calibrate the HV supply

Install the 30 amp. Fuse
Connect a 100 uf 10 KV capacitor to J3
Turn the supply on
Set the digidial to 2 KV and depress the charge button. Verify that the system charges to approximately 2 KV and stop.
Repeat above step for 8KV. If supply does not stop at 8 KV exactly, adjust R12 on the logic board.
Repeat the above step for 9.5 KV
turn the supply off; discharge the capacitor bank and connect the electrostatic voltmeter from ground to J3 (connect to the solder connection of J6, DO NOT REMOVE THE CAPACITOR BANK) and verify that the supply meter agrees with the electrostatic voltmeter.

To check out the remote connector.

Turn power off
Using the RX1 scale on the ohm meter, verify that
Pin 1 in J2 connect to TB1-4
Pin 2 in J2 to TB1-5
Pin 3 in J2 to TB1-2
Pin 4 in J2 to TB1-8
Pin 5 in J2 to TB1-7
Turn power on
Connect a remote cable to the system and verify that the system charges, pumps and when the fire button is depressed 34VDC appears on Pin 4 on TB1