Audible Circuit Probe
Use to check
- AC & DC Voltages
- Resistors to 1 meg ohm
- Capacitors to 3000 mfd
- Diodes & Transistors
- Compare Circuit Resistance
The Circuit Probe produces a tone that varies with resistance, capacitance, or voltage. May be used to check continuity, compare circuit resistances, check capacitors, diodes or LED and trace audio signals (up to 1 KHz). Will test live circuits up to 130 VDC or AC (AC is modulated tone). Because the probe is current limited, it will not generate the high current surges normally produced by lamp and buzzer type testers. The probe will not harm any circuit. Sharp pointed tip on one end and a minigator clip on the other. Cable length 36". 9 Volt battery included. Size 7" x 1.2" x 0.9"
Safe for Semiconductors & CMOS Logic
(probe is current limited to 500ua.)
0 Resistance (probes shorted)= "REFERENCE TONE"
As resistance goes UP to 1 meg ohm, Frequency goes DOWN to 10Hz.
DC & AC Voltage
DC RANGE- 0-130 volts MAX
0 volts- "REFERENCE TONE"
To +130 volts- Frequency goes UP with voltage
To - 8 volts- Frequency goes DOWN with voltage
AC RANGE- 0 to 130 volts MAX
Frequency goes UP with voltage, and is an AC modulated tone.
NON-POLARIZED CAPACITORS (ceramic, mylar, ect.)
Less that .01 mfd. - No Tone
.01 to .5 mfd. - One click
.5mfd to 3000mfd. - Tone changes from High Freq. down to 10hz.
POLARIZED CAPACITORS (electrolytic & tantalum)
Same indications as above if connected this way.105-c.jpg
If leads are reversed, tone will only go down to "REF. TONE" and possibly start back up.
1. Before testing, short capacitor leads together to discharge.
2. Ceramic capacitors may have buzzing sound depending on leakage
3. Capacitor is shorted if "REF. TONE" is heard in both directions.
Diode- Zenner- LED- Rectifier
"Reference Tone will be heard"
WITH LEADS REVERSED DIODES
1 to 3hz may be heard because of leakage
Up to 20hz is acceptable of normal leakage
TRANSISTOR GOOD-When connected as above, and a tone slightly lower than "REF. TONE" is heard.
TRANSISTOR OPEN- No tone, when connected as above.
TRANSISTOR SHORTED- If tone is heard when leads are reversed.
2 Reviews Hide Reviews Show Reviews
I put this to use right away on a field job for a Fire Dept. client, while servicing a Fire Stations Dispatch audio and activation system. I was very tickled at how I could quickly and easily verify the systems AC line voltage, DC supply voltage, ground and operational continuity! I originally purchased this item out of curiosity plus to patron an American Mfr'd product.
This is faster than a meter, you don't even need to turn it on. You can find intermittents by listening to the sound as you manipulate your device. Some ac plugs will fail with a lose pin, you will hear a tick tick sound when that happens. Its also good for to check any light bulb or both input and output of a wall wart. Its a great electrician tool as well, instantly check a switch or if power is present.