COMPONENT CHECK
1. Be sure that all components have been mounted in their correct places.
2. Has the LED D1 been installed correctly? The flat side of its body should be in the hole as shown on the top
legend. If the LED is in backwards, it will not light.
3. Pay close attention to the red and black wires of the battery snap. The red wire should be installed in the
positive (+) hole and the black wire in the negative (–) hole. Snap in a fresh 9-volt battery.
OPERATING THE K-20
1. Grasp the probe so that you touch the copper on both sides of the probe.
2. Try to guide the loop along the wire. If the
loop touches the wire, you will receive a
mild shock or throw the slide switch S2
and the LED will light instead.
3. Push switch S1 to reset the LED.
TROUBLESHOOTING
Contact Elenco Electronics if you have any problems.
DO NOT contact your place of purchase as they will not
be able to help you.
1. One of the most frequently occurring problems is poor solder connections. Tug slightly on all parts to make
sure that they are indeed soldered.
2. All solder connections should be shiny. Resolder any that are not.
3. Solder should flow into a smooth puddle rather than a round ball. Resolder any connection that has formed
into a ball.
4. Have any solder bridges formed? A solder bridge may occur if you accidentally touch an adjacent foil by
using too much solder or by dragging the soldering iron across adjacent foils. Break the bridge with your
soldering iron.
LED CIRCUIT REMEDY
1.
LED - Move switch S2 into position A (shown on the top legend drawing in the assembly manual). Place a clip-
lead from the cathode lead of the LED (the lead on the flat side) to the negative terminal of the 9-volt battery.
The LED should light. If the LED does not light, the problem is with the LED or resistor R1. If the LED is
installed with the flat side in the correct direction and R1 is the correct value, then most likely the LED is at fault.
2.
SCR - Move switch S2 into position A. Place a clip-lead from the gate (G) of the SCR to the positive
terminal of the battery. The LED should light even when the clip-lead is removed. If not, the problem
could be with S1, be sure that S1 is in the open position first. If you get no response, place a clip-
lead from the center lug to the position A lug of switch S2. If the circuit works now, the problem was
S2. If the circuit still does not work, the problem is the SCR.
SHOCKER GENERATOR REMEDY
1.
TRANSFORMER - Be sure that the transformer is installed correctly, with the three lead side in the direction
as shown in the top legend drawing in this manual.
2.
S2 - Place a clip-lead from the center lug to position B. If the shocker circuit now works, the problem is with S2.
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