Archive for the ‘Testing and Measurement’ Category
Another RF Field Strength Meter

This circuit is another radio frequency (rf) field strength meter, similar with our previous field strength meter circuit, but with lower supply voltage (only a single cell 1.5V battery). Here is the schematic diagram of this rf strength meter circuit: To use, turn on transmitter and meter; adjust C1 for peak reading. Turn off …
Field Strength Meter

This instrument is very useful for radio frequency (rf) engineer and hobbyist, especially when he/she has to adjust the final rf transmission. Setting up an antenna impedance matcher is one of the example. Here is the schematic diagram of this rf meter circuit: The circuit use only one transistor (MPSA18) as the active component. The …[Read More]

Thermocouples give many benefits compared to thermistor/RTD (Resistance Temperature Devices). Some advantages of thermocouple are their wider temperature range, their reliability, and their consistency over long period of time. In some cases, thermocouple calibration is even unnecessary. Thermocouple temperature sensors are widely used in temperature controllers for boilers, oven, pressurized reactor, even in high temperature …[Read More]
Infrasonic and Ultrasonic Filter for High Fidelity (Hi-Fi) Audio System

In high fidelity (hi-fi) audio system, the harmonic distortion level is kept as low as possible. To make sure that the amplifier handle the sigal perfectly, the response of many hi-fi audio systems is designed beyond the audio range, include the handling capability to process infrasonic (below 20Hz) and ultrasonic (higher than 20kHz) signals. Although …[Read More]
Pt100 RTD Current Loop Transmitter Using XTR105

XTR105 is a 4-20mA current loop transmitter integrated circuit, with two precision current sources. The Instrumentation amplifier gain inside this chip can be configured for a wide range of temperature or pressure measurements. This integrated circuit chip provides current excitation for platinum RTD temperature sensors and bridges, instrumentation amplifiers, and current output circuitry on a …[Read More]
RCV420: Single Chip Precision 4-20mA Current Loop Receiver

RCV420 is a special function integrated circuit chip for 4-20mA current loop receiver. RCV420 provide complete 4-20mA to 0-5V conversion, with 0.1% overall accuracy, 86dB CMR, and ±40V common-mode input range. This IC chip is suitable for many applications: PROCESS CONTROL INDUSTRIAL CONTROL FACTORY AUTOMATION DATA ACQUISITION SCADA RTUs ESD MACHINE MONITORING Here is the …[Read More]
Audio Power Meter: Shows Your Audio Amplifier’s Actual Output Power

Using this circuit, you can measure the actual output power of your amplifier. You can put this circuit in a box as a measurement instrument, or you can integrate it inside your power amplifier to get real power display. The circuit’s schematic diagram is shown in the figure below. This circuit would be a handy …[Read More]
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