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This is an adapter attached to a TV set. This machine changes a TV to a Oscilloscope. See the photo! This photo indicates a sine wave 50mV 120Hz. See the circuit! Free oscillater makes an 15kHz pulse signal (A). This signal is amplified by an buffer AMP. On the other hand , an amplifier makes 300 times of input signal. And it is shifted to 6V center. A comparater compares a voltage (C) and (B). this comparater makes an pulse width modulated signal on (D) point. Differencial circuit makes a small pulse on the changing timing of the pulse. Buffer receives two signals ,(A) and (E). Therefore it is called as an adder. This machine is able to indicates only 60Hz or 120Hz or 180Hz

USB Voltmeter is a PC based dual channel voltmeter built around PIC18F2455 / PIC18F2550 microcontroller that measures voltage from 0.00V up to 500.00V with 10mV resolution. USB Voltmeter sends measured data to PC via standard USB connection displaying data on a computer monitor. USB Voltmeter is self-powered drawing very little current from USB port. Voltage readings are displayed via included USB Voltmeter software.

Everyone involved with radio transmitters needs some instruments to assess basic antenna functionality. Among these instruments, the best-known and most-used one is the Standing Wave Ratio meter. Some radio amateurs develop a cult for these little gadgets, having them in line all the time and watching the needles bounce while they chat. I have seen some guys owning 5 or 6 SWR meters, and no other instrument relating to antenna testing! While it's unfortunate that some people - specially amateurs - assign so much importance to SWR and so little to other parameters, it's also a fact that SWR needs to be known, so if you use transmitters, you need an SWR meter.

This project is based on obdev's RemoteSensor example and their firmware-only USB implementation; the main change is the replacement of the analog sensors with a Sensirion SHT11 digital temperature and humidity sensor.

The sensor unit consists of an ATTiny45 microcontroller, a SHT11 sensor, and a hoperf RFM12 868 MHz transceiver module. It is powered by 2 AA cells and is expected to give >1 year of battery life. The receiver uses the same RFM12 module and an ATMega8 µC; received data is transmitted via USB to the PC.

Presented here is XR2206 function generator with multiple waveform selection and a frequency readout display. The diagram on the right shows the internal workings of the XR2206 in the form of a block diagram. Essentially the chip contains A VCO (voltage controller oscillator), wave shaper and buffer. The xr2206 frequency generator diagram frequency of the VCO is set with a capacitor and a resistor. The capacitor sets the frequency range whilst a variable resistor can be used to vary the frequency in the set range. The frequency is defined by ƒ = 1/(RC). For a starting point for the design of the frequency generator I used the test circuit from the XR2206 datasheet. I built this on bread board and experimented with the timing resistor and capacitor and managed to get the frequency up to 4MHz.

Presented here is a premium quality 1Hz - 2MHz XR2206 Function Generator kit capable of producing high quality sine, square and triangle waveforms of high-stability and accuracy. The output waveforms can be both amplitude and frequency modulated. Coarse frequency adjustment is accomplished using 4-DIP switch for the following four frequency ranges; (1) 1Hz-100Hz, (2) 100Hz-20KHz, (3) 20KHz-1MHz, (4) 150KHz-2MHz. Frequency output can be fine tuned using P1 and P2 potentiometers. The kit includes output that can be connected to 60MHz Counter kit to measure output frequency. 1Hz - 2MHz XR2206 Function Generator kit includes premium quality components, including Audio Grade Capacitors, Gold Plated RCA Connector, WIMA Capacitors, 1% Metal Film Resistors and premium quality PCB with red solder mask and plated through holes.

There are integrated circuits that produce sine waves, although they are really relaxation oscillators and the sine waves come from shaping a triangle wave. Examples are the ICL8038, which is good up to about 100 kHz, and the newer XR-2206 and XR-3038, which can oscillate up to 1 MHz. The XR-2206 has some interesting features that illustrate some of the topics mentioned in this page, so let's examine this chip.

Presented here is zener diode meter for testing voltage value of an unknown zener diode. The zener diode or diode voltage regulator is a special diode, Unlike normal diodes these diodes are intended to work in the breakdown voltage and an essential part of the voltage regulator circuits. These components maintain constant voltage at its terminals suffer variations even when substantial current, its connection with reverse bias is normal also to work in the zener voltage of the source Vs must be greater than the rupture Vz, as always condition using a resistance Rs in series to limit current to a value always less than its maximum power.