HiFi expandor with De-emphasis

Single-Chip Dc Supply Circuit

Direct derivation of 5 to 24 Vdc from ac mains, without a transformer is possible with tiiis circuit. Note that a direct mains connection to the dc output exists.

Steam locomotive whistle

The waveform of a steam whistle is a complex combination of white noise and an audio frequency oscillation. The noise generator is a transistor (Ql) biased into zener mode. The audio frequency oscillation is a straightforward mixture of two similar (but not identical) sine waves, which after...

Line-synchronized-driver

The gate drive that phase controls the four parallel SCRs is accomplished with complementary MOS hex gate MC14572 and two bipolar transistors. This adjustable line-synchronized driver pennits SCR conduction from near zero to 180 degrees. A Schmitt trigger clocks a delay monostable multivibrator...

Low-Drift/Low-Noise Dc Amplifier

Figure 39-2"s circuit combines a low-noise op amp, IC1, with a chopper-based carrier-modulation scheme to

Code-Practice Oscillator Iii

Capacitor CI charges through resistor Rl, and when the gate level established by potentiometer R2 is high enou

Ring-detector

This circuit detects the 20 Hz, "" 86-V rms ring signal on telephone lines and initiates action in an electrically isolated circuit. Typical applications would include automatic answering equipment, and interconnect/ interface and key systems. The circuits illustrated are bare bones circuits...

Spare-flip-flop-inverter

The circuit uses one-half of a dual D flip-flop as an inverter. When the input decreases, the flip-flop resets, and its Q output increases. When the input increases, the reset line is released and Q gets clocked low. The rc delay between applying the input signal to the flip-flop"s reset input...

Power meter 1KW

The circuit is intended for 117 Vac ± 50 Vac operation, but can be easily modified for higher or lower voltages. It measures true (nonreactive) power beingdeliveredto the load and requires no external power supply. Idling power drain is only 0 W. Load current sensing voltage is only 10 mV,...