The schematic diagram below describes a simple continuity tester circuit. This circuit is used to test if two point is electrically connected by sounding a tone, which the pitch is inversely proportional to the resistance of the tested points. This circuit is designed for high resistance circuit, but however, this circuit can be used for low-resistance circuits. The multivibrator’s frequency is influenced by the resistance between the tested points, and this multivibrator is formed by classic flip-flop circuit Q2 and Q1. The output stage Q4 and Q3 drive a telephone earpiece or a small loudspeaker. Here is the schematic diagram of the circuit:
Possibly Related Articles:
- RS Flip-Flop Using OP-AMP
This RS flip-flop is op-amp version of classic flip-flop which uses two inverting amplifier. The non-iverting input is floating, and we can assume that the voltage level of this floating... - Multilevel Continuity Tester
This continuity tester not only show if a connection is continue or not, but also determine the range of its conductivity level. Here is the schematic diagram of the circuit:... - Voltage and Current Limited Audible Continuity Tester
Using this continuity tester circuit, a failure of PCB tracks be examined without looking directly at the tracks routing, which is can be very frustrating. The indication of this circuit... - Current Sense Circuit, A Classic Design Using Positive Rail Sensing
A LT1637 is advertised as 1.1MHz, 0.4V/us Over-The-Top Micropower, Rail-To-Rail Input and Output Op Amp. This features are suitable for current sensing application since input voltages are right at the... - Simple Transistor Tester Using 555 IC
Testing whether a transistor is shorted or open usually done by ohm meter. You test if the base to emitter or collector permit a current flow in one direction. Here... - In-Circuit Automotive Fuse Tester
This is a schematic diagram of auto fuse monitor circuit. This circuit is very useful for automobile application, checking a live fuse without wasting any electrical power if the fuse... - Cable Reflection Tester
This is a Cable Reflection Tester circuit. This circuit can be used to check coax cable runs for shorts or even impedance mismatches. This circuit will send a pulse down... - Mosfet Tester
This circuit included in the category astable multivibrator. This circuit is used to test N-Mosfets (the power kind e.g irf830), whether it works or not. If it is not working,... - Crystal Tester
A crystal tester circuit is very simple, it contains only oscillator and detector inside. This crystal tester circuit uses one transistor for the oscillator and one transistor for the detector.... - 74HC11 Infra-Red Remote Control Tester
This is Infra-Red Remote Control Tester circuit. This circuit is used to test go/no-go of any remote control transmitting infra-red (IR) light. The supply of this circuit is 3V battery.... - Simple PWM Circuit Using Inverter Gates
This PWM circuit needs only two inverter gates, so you can build up to 3 independent PWM circuit using only one IC chip, since there are at keast 6 inverter... - A Simple Metal Detector Circuit Using Beat Frequency Oscillator (BFO)
Metal Detector Circuit Topology One of the simplest method of metal detecting is by beat frequency oscillator. Basically, the circuit consist of two balanced oscillator. One oscillator provides the reference...
| 
