Table of Contents
Advertisement
You have completed wiring the Audio Amplifier. We shall proceed in testing this circuit. You will need for static
measurements, a Volt-Ohm-Milliammeter, preferably a digital type.
STATIC MEASUREMENTS
RESISTANCE TEST
Adjust the Volt-Ohm-Milliammeter (VOM) to the highest
resistance scale available. Connect the VOM to pin 6 of
the IC as shown in Figure 6. Do not connect the battery.
The VOM should indicate a low resistance first and then
as
C14
charges,
approximately 4MΩ. If you get a lower reading, reverse
Amps
COM
TP8
Figure 6
POWER UP TEST
Set your VOM to read the highest possible current.
Connect the meter to the circuit as shown in Figure 7.
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.
DC Amps
+
Amps
Figure 7
resistance
should
Ω
V/Ω
COM
V/Ω
multimeter leads.
100kΩ, 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 10MΩ,
rise
to
check for open copper or bad solder connections on all
components.
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 3 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.
-11-
If you get a reading lower than
Advertisement
Table of Contents
