This power amp has a power output of 400 w Power supply Voltage amps 400 w + / – 70v and 1.5 V input sensitivity If you want a power amp 400 w choose the perfect audio component of good Read Full Story

EPROM progrogramer does NOT use any device to output a voltage to the PC printer port, only a current sink. All inputs from the printer port are buffered. In this way there is little or no possibility of damage to the printer port, even with most wiring error possibilties during construction. This EPROM burner will handle most standard EPROMS, but some switching may be required by the constructor at the EPROM socket. I will leave that up to you, although I do give some advice on this subject... Read Full Story

This power amp has a power output of 150 W (8 ohms) or 200 W (4 ohms) Voltage supply + / – 52v and 1.5 V input sensitivity If you want 150W Power Make perfect audio amps choose good quality components Read Full Story

It is a simple Colpits oscillator, but it has a 78L05 5v regulator (not shown) as the supply feed. The 22K and 33K resistors bias TR1 emitter to about 3v DC, which means that TR1 emitter can feed the CD4040 counter input directly when the synth is fed from a 10 volt supply. This is the “sense” output. TR2 is a buffer with an additional 4K7 base feed resistor to further buffer the oscillator from the output stage. The output from TR2 emitter is about +10dBm. L1 determines the freq... Read Full Story

Given that the diode can be made to conduct, or not to conduct, simply by the choice of applied voltage polarity, then it must be possible to use any diode as a switch. So if you want to follow me, then just wire together the following circuit on a bit of breadboard, or something. Set the signal generator to 1v RMS (3v peak-to-peak) at 1kHz. Set the oscilloscope to 1v/cm and set the timebase to 200uS/cm (0.2uS/cm). You will see an undistorted sinewave on the scope, and having an amplitude of... Read Full Story

When switching an antenna between a transmitter and receiver, the 1N914 or 1N4148 can still be used, but with decreasing success as the frequency rises. It is common practice in VHF transcievers to use a PN junction diode, but with a lightly doped “Intrinsic” region between the P and N layers. The diode is called a PIN diode. When the PIN diode is made to pass a current it has a low resistance, just like a normal PN diode. But when the curren is removed, there is a delay when char... Read Full Story

Now I shall introduce my somple diode counter. To start off with, the MC145152-2 A-counter can have a count of 512, 1024, or 2048. This means that a 12.8MHz crystal, divided by 1024, will give you a reference frequency of 12.5kHz. You could alternatively use 6.4MHz divided by 512. Not many options there! You still need to buy a special crystal. In my counter you can divide by ANY number from 2 to 2047. I put my hand in my junk-box and fished out a 5075kHz crystal. I can get 25kHz from that b... Read Full Story

TTL RS232 driver circuit. TTL driver circuit consists of 2 transistors and a few other passive components, a negative voltage for RS232 logic generated by the capacitor C7. TTL to RS232 driver circuit and a variable voltage output driver has a parallel termination impedance to match cable and TTL driver circuit, and provides the best waveform. When driving to the RS232 TTL driver circuit or a variable input voltage, a source termination impedance matching the cable will give the best results.... Read Full Story

Making Wireless FM microphone as a beginner project is interesting, crystal oscillator can be controlled, with a harmonic change to 2p7-5 crystals. The oscillator will then be very stable, so stable in fact, that he could not even set! This means you can only use it to send CW .One solution to this problem would be to use a low frequency crystal oscillator and modulate it. Because the crystals can be modulated by typically only 1kHz or 2KHz, then the multiplication factor should be around 72.... Read Full Story

Switching regulator and linear regulator circuit for all electronic resources Switching regulators is an inductor stores energy, Energy Switching regulators can be expressed in Joules as a function of current. A switching regulator inductors have no voltage drop and current flow-related but 90 degrees out of phase with the voltage. Because of this, energy can be saved and restored in the implementation phase of the switching cycle. Switching regulator circuitry that uses the power switch, an ... Read Full Story