Rpm80 Inductive Pickup Test (Optional Accessory) - Fluke 78 Service Manual

78
Service Manual

3-24. RPM80 Inductive Pickup Test (Optional Accessory)

To test the RPM-80 inductive pickup, a triangle wave from a Function Generator will
simulate automobile spark plug signals on a loop of wire containing a 10-ohm resistor.
The pickup will be clamped to the wire, and output voltage from the pickup will be
monitored by an oscilloscope.
To test the RPM80 Inductive Pickup, proceed as follows, referring to Figures 3-4 and 3-
5 as necessary:
1. Solder a 10-inch piece of 14 or 16-AWG wire to one end of the 10-ohm resistor.
2. Connect the other end of the resistor to the LOW and the wire to the HIGH of the
3. Connect a 10X-scope probe from channel 2 (dc-coupled) of the oscilloscope across
4. Clamp the inductive pickup to the wire loop as shown in Figure 3-4. Make sure that
5. Connect a 10X-scope probe from channel 1 (dc-coupled) of the oscilloscope across
6. Set up the Function Generator as follows:
7. Set channel 2 of the oscilloscope for 0.5 V/DIV at 0.5 µs/DIV time base.
8. Trigger channel 2 on the triangle waveform. Adjust the amplitude of the Function
9. Set channel 1 of the oscilloscope for 1.0 V/DIV at 5 ms/DIV time base.
10. Trigger channel 1 on the inductive pickup waveform. Adjust the Function Generator
11. Check that the peak voltage is greater than 5.5 V and decays to less than 1.0 V
12. Turn the inductive pickup so that "SPARK PLUG" points toward the LOW output of
3-14
binding-post-to-BNC adapter. Connect the adapter to the output of the Function
Generator. See Figure 3-4.
the 10-ohm resistor (not across the Function Generator output).
the jaws of the inductive pickup are closed completely, and that the side of the
pickup which says "SPARK PLUG" points toward the HIGH output of the Function
Generator.
the output of the inductive pickup.
FREQ RANGE Hz
FREQUENCY
ATTENUATION
MOD/SWEEP PERIOD s
MOD/SWEEP PERIOD s
MODE
WAVEFORM
CONT
LIN
DUTY CYCLE
OUTPUT
PERIOD
PERIOD
START PHASE
DC OFFSET
Generator for an output of 3 V peak. See Figure 3-5.
PERIOD for a 10 ms repetition rate.
between pulses. See Figure 3-5.
the Function Generator. Check that the waveform is less than 2 V.
2M
0.600 MHz
None
.1 (PM5133)
10 ms (PM5134)
SINGLE
Triangle
Out
In
Out
50 Ohms
Halfway (PM5133)
x1 (PM5134)
π/2
In