Digital Altimeter Circuit
A pressure sensor (IC4) is used with a dc: amplifier to convert the bridge output (IC4) to a single-ended voltage. ICld provides a reference voltage for settin...
Rc Decade Box Circuit
This decade box can be set for any resistance value between 10 and 11.1 in 10- stops. A switch can be used to configure several RC configurations. Use close ...
Visual Continuity Tester Circuit
By judging the rate at which a particular LED flashes, you`ll be able to estimate the resistance. The circuit consists of two IC`s (1 4011 CMOS quad 2-input, N...
Watch Tick Timer Circuit
This circuit adapts a frequency counter to measure intervals. It was originally used as a shutter speed checker for a photo application. The watch ticks are cl...
Harmonic Distortion Analyzer Circuit
The circuit includes a low-distortion, 1-kHz oscillator and will measure THD at a user selected voltage level for voltage amplifiers, or for checking amplifier...
Energy Consumption Monitor Circuit
The ECM circuit consists of four sections, as shown in the block diagram. A power converter generates a voltage that is proportional to the true of real power ...
Current Source For Resistance Measurements Circuit
Useful for low-resistance measurements, this 1-A current source will produce 1 A in unknown resistance Rx. For best results, R,c should be less than 1 to 2, be...
Easy Crystal Impedance Checker Circuit
On occasion, microprocessors/microcomputers and microprocessor crystals just aren`t compatible with each other. Many microprocessor data sheets specify maximum...
10Mhz Frequency Counter Circuit
The circuit consists of an ICM7208 seven-decade counter (Ul), an ICM7207A oscillator controller (U2), and a CA3130 biFET op amp (U3). Integrated circuit Ul cou...
2Mhz Frequency Counter Circuit
This is a schematic and block diagram of a 2-MHz frequency counter. It uses and LSI counter/display driver, LCD readout, and a few logic chips for timebase and...
Bargraph Led Battery Tester Circuit
The LM3914A bargraph LEDis used here as a voltmeter for battery testing. The circuit is powered by a 4.5-V battery and compares the battery under test with an ...
Universal Test Probe
The compact test probe provides rapid "measurement" of voltage levels at digital gates, fuses, diodes, batteries, and ...
Multi-Tester Logic Probe Signal Tracer And Injector
This circuit for a test set contains a signal injector (U1A/U1B) and associated com...
Isolated Voltage Sensor
A simple voltage-controlled oscillator (VCO), coupled to your instrumentation by an optoisolator, allows you to mea...
1-Ma Current Sink
A fixed current flows through any load that is connected between the positive supply and Ql"s collector. The noninverting...
Cassette Motor Speed Calibrator
This frequency/voltage converter enables calibrations of cassette-deck speed. It records a steady 1-kHz ton...
Frequency Counter
Built around an Intersil 7216 frequency-counter IC, this counter has a basic range of 10 MHz, a 100-MHz prescaler, and an...
Continuity Tester
A continuity tester that has an audible indicator can be more useful in some cases than a visual indicator, because you n...
Dc Millivoltmeter
An LF356 op amp is used as a gain amplifier with the output taken across R5, When a full-scale current of 1 mA is flowing...
Led Millivoltmeter
This circuit uses a dc amplifier (324) in a bar-graph circuit that uses an LM339 Quad comparator IC to sense dc levels. ...