Elenco Electronics AM-550TK Instruction Manual download pdf (Page 11)

STATIC MEASUREMENTS

RESISTANCE TEST

-10-

DC Amps

Amps COM V/Ω

Amps

COM

V/Ω

GND

R15

You have completed wiring the Audio Amplifier. We shall proceed in testing this circuit. You will need a Volt-Ohm-

Milliammeter, preferably a digital type.

Adjust the Volt-Ohm-Milliammeter (VOM) to the highest

resistance scale available. Connect the VOM to the

circuit as shown in Figure 3. Do not connect the battery.

The VOM should indicate a low resistance first and then

as C14 charges, resistance should rise to

approximately 100kΩ. If you get a lower reading,

reverse multimeter leads. If you get a reading lower

than 20kΩ, check the circuit for shorts or parts inserted

incorrectly. Check C14 to see if it’s leaky or inserted

backwards. If you get a reading higher than 150kΩ,

check for open copper or bad solder connections on

resistors R13 and R14.

Figure 3

Figure 4

Set your VOM to read the highest possible current.

Connect the meter to the circuit as shown in Figure 4.

Make sure that the On/Off switch (SW1) is in the OFF

position.

While watching your VOM, flip switch SW1 to the ON

position. The VOM should indicate a very low current.

Adjust your meter for a more accurate reading if necessary.

If the current is greater than 25 milliamps, immediately turn

the power off. The current should be between 5 and 15

milliamps. If you circuit fails this test, check that all parts

have been installed correctly and check for shorts or poor

solder connections. Turn OFF SW1.

POWER UP TEST

1 2 ... 6 7 8 9 10 11 12 13 14 15 16 ... 31 32

No comments

Elenco Electronics AM-550TK Instruction Manual Page 11