Wiparat Circuit Electronics

A high qualitiy voltage regulation must be built using high quality parts. It is however no longer necessary to use discret semiconductors as there are now very good integrated voltage regulator ciurcuits available. I chose the adjustable regulators LT1085 (positive) and LT1033 (negative) which are compatible to LM317/LM337. The standard fixed voltage regulators of the 78xx and 79xx series produce much higher noise and have worse ripple suppression, although you can find those even within highend preamplifiers (Bryston 25 BP). Link

Other Link
Flyback Driver Circuit with 2N3055
High Current Regulated Supply by LM317
0-30 V DC Power supply with current control 0.002-3 A
High voltage spill equal DC 900V

Use this circuit as a low cost alternative to a commercial DAC. It is important that the latch be a CMOS device, so that the outputs drive to Vcc when they are high. (TTL devices only drive to 2.4 volts or so). I have shown the ‘573 latch rather than the ‘373 which can also be used. The ‘573 has the advantage of sequential pin-outs for the Q0 - Q7 pins, making it easier to connect in most circuit layouts.The LM358 OpAmp is a good choice for this circuit for two reasons: 1) It can be powered from the 5V supply. 2) Its output can go to 0V without a negative power supply. Note that the LM358 is a dual OpAmp, so the other half is unused in this circuit. Link

Other Link
Stepping Motor Driver using XNOR gate
Standard Touch Switch by IC Gate 4011
Bounceless Switch by IC 555
Digital Step-Km Counter with IC 4026,4024

If your stereo amplifier does not have an input for a record player, you should use this circuit between your turntable and your amplifier. The output of your turntable follows a gain-bandwidth curve called the RIAA compensation curve. The standard AUX input on your stereo does not. Records will sound very strange without an RIAA preamp. Link

Other Link
Op-Amp Microphone Preamp by NE5534
Vinyl Pre-Amplifier with NE5534
Doorphone Intercom with LM386
35W Hi-Fi AUDIO POWER AMPLIFIER by TDA2050