Introduction
APPLICATION of the transistor to A electronic circuitry is a striking ample of technological progress. Eight years prior to this writing, very few knew how the transistor worked and some were openly skeptical of its future. Today, many people need transistor circuit information. They range all the way from the scientist and engineer to the casual experimenter.
This book is a collection of practical transistor circuits, each of which has been tested by the author in his own laboratory. These circuits are presented with the expectation that they will save many hours of design time. As building blocks with values already worked out, they may be employed singly or (in systems) in combi- nation with each other or with other circuitry. Slight modifications of component values will allow the reader to obtain results different from those originally intended. A study of the chapter headings will show that an effort has been made to cover a wide range of interests.
The circuits in this book have been designed by many persons or are based upon their inventions. No claim is made or implied that they are of the author’s invention. Transistorized circuits have be- come so numerous that already their use is becoming “customary.” That is, a certain circuit becomes so useful and commonplace (even as with vacuum-tube circuits) that eventually the originator’s name is dropped, although no less respected.
No space is devoted to theory, except in occasional instances where it appears necessary for a clear understanding of the circuit under discussion. For a general treatment of the subject of tran-sistors, the reader is referred to the author’s book Transistors, Theory and Practice from the same publisher. Several of the circuits have been taken from articles which have
appeared previously under the author’s name in various magazines. These are listed as references at the end of each chapter so that the reader might explore the subject more extensively. For permission to use this material, the author is grateful to the editors of Audio- craft, Electronics, Popular Electronics, RADIO-ELECTRONICS Maga- zine, Radio & Television News and Tele-Tech & Electronic In- dustries.
CHAPTER 1. AUDIO AMPLIFIERS
Single-stage, R-C-coupled, common-base amplifier. Single-stage, trans- former-coupled, common-base amplifier. Single-stage, R-C-coupled, common-emitter amplifier. Single-stage, transformer-coupled, common- emitter amplifier. Single-stage, R-C-coupled, common-collector ampli- fier. Single-stage transformer-coupled, common-collector amplifier. Multistage, R-C-coupled amplifier. Multistage, transformer-coupled amplifier. Push-pull pull output circuits. Phase inverters. Class-B loud- speaker amplifier with conventional transistors. Class-B loudspeaker amplifier with power transistors. Class-A loudspeaker amplifier with power transistor. Complementary-symmetry power amplifier with con- ventional transistors. Complementary-symmetry power amplifier with power transistors. Single-stage low-noise preamplifier. Preamplifier with high-impedance input. Boosting transistor input impedance.
CHAPTER 2. . RF AND IF AMPLIFIERS
Broadcast-band rf amplifier and preselector. Single-stage, single-tuned 455-kc if amplifier. Two-stage, 455-kc if amplifier. 50-kc if amplifier. Transistors for high-frequency rf amplifiers.
CHAPTER 3. DC AMPLIFIERS
Single-stage current amplifier. Single-stage current amplifier with fixed-resistance input. Cascaded p-n-p current amplifier. Cascaded p-n-p -n-p-n current amplifier. Single-stage, de voltage amplifier. Cascaded de voltage amplifier. Single-stage, power-type current amplifier. Two- stage, high-gain, power-type current amplifier. Alpha-beta conversion.
CHAPTER 4.. OSCILLATORS
Single-frequency audio oscillator. Simple code-practice oscillator. Loud- speaker-operating code-practice oscillator. Phase-shift audio oscillator. Step-type variable-frequency audio oscillator. Tuned, variable-frequency audio oscillator. 100-kc crystal oscillator. Self-excited 100-kc oscillator. High-frequency crystal oscillator. Self-excited rf oscillator. Wide-range rf oscillator. Multivibrator. Blocking oscillator. Light-powered oscilla- tors. Oscillator operating notes.
CHAPTER 5. POWER SUPPLIES
Variable low-current de power supply. Variable high-current de por er supply. Full-wave variable dc power supply. Light-duty de voltage regulator. Heavy-duty de voltage regulator. Light-duty constant-current adaptor. Heavy-duty constant-current adaptor. High-voltage dc-to-dc power supply.
CHAPTER 6. RADIO RECEIVERS
Single-transistor broadcast receiver. Two-transistor broadcast receiver. Miniaturization of simple broadcast tuners. Regenerative broadcast receiver. Step-tuned diode-transistor broadcast receiver. Push-pull transistor broadcast receiver, Loop-operated diode-transistor broadcast receiver. Sun-powered broadcast receiver. Superheterodyne broadcast receiver. All-wave regenerative receiver. High-frequency cueing receiver.
CHAPTER 7. TRIGGERS AND SWITCHES
Flip-flop. One-shot multivibrator. Pulse delay circuit. Simple co- incidence circuit. Pulse inverter.
CHAPTER 8… CONTROL DEVICES
Sensitive de relay. Ultra-sensitive dc relay. Sensitive switching circuit for light-duty contacts. Sensitive ac relay. Sensitive rf relay. Ultra- sensitive rf relay. Heavy-duty relay booster. Sensitized heavy-duty relay booster. Sound-operated relay. Light-operated relay. Photoelectric counter. Phototimer. Miniature-motor control. General-purpose radio control relay. Carrier failure alarm. Inpulse counter.
CHAPTER 9. TEST INSTRUMENTS
Low-gain single-transistor de microammeter. Zero-setting circuits for microammeter. High-gain de microammeter. Supersensitive de microam- meter. Electronic de voltmeter. Audio voltmeter-millivoltmeter. Milli- volt adaptor for ac vacuum-tube voltmeter. Sensitizer for high-range dc milliammeter. TV antenna compass. TV field-strength meter. Bridge null detector. Sharply tuned null detector. Crystal-type sound marker generator. Audio signal injector. Crystal-type set aligner. Rf signal generator. Radio-frequency comparator. Heterodyne frequency meter. Sound-level [noise) meter. Af-rf signal tracer. “Grid”-dip oscillator. Low-frequency “grid”-dip oscillator. “Grid”-dip adaptor. Sensitive light meter.
CHAPTER 10. AMATEUR DEVICES
Keying monitor. Phone monitor. Speaker-type dynamic microphone. Signal peaker (CW filter). Field-strength meter. Modulation monitor. CW transmitter. Conelrad receiver. Transistors in conventional amateur receivers.
CHAPTER 11. MISCELLANEOUS CIRCUITS
Simple Geiger counter. Geiger counter with transistorized high-voltage supply. Phono oscillator. Wireless microphone. Photoelectric intrusion alarm. Transistorized 0.6-watt intercom. Hearing aid. Diode-type transistor power supplies. Safety diode for transistor circuits.
