Although radios are common enough and cheap, why not make your own from a few readily available components? For example, the design shown in Fig is uncomplicated thanks to the two integrated circuits, IC1 and IC2, and it will receive radio stations transmitting amplitude modulated (AM) radio … [Read more...]
The full circuit diagram for the Simple FM Radio is shown in Fig.1. It consists of a regenerative r.f. stage, TR1, followed by a two or three-stage audio amplifier, TR2 to TR4. In some areas three stages of a.f. amplification may not be necessary, in which case transistor TR3 and its associated … [Read more...]
In the preceding Hearing Aid project, the output of the amplifier is used to drive a crystal earpiece, which is fine for personal listening but very often a loudspeaker provides a better output device enabling a number of people to listen simultaneously, or for the sound to be heard from a distance. … [Read more...]
It is not intended to be used as an alternative to medically approved hearing aids. This simple design consists of a microphone and a three-stage transistor amplifier. It has a manual volume control and is powered by a 9V PP3 battery. Its circuit diagram is shown in Fig.. The microphone (MIC1) is a … [Read more...]
We can increase the voltage gain still further by connecting two similar circuits as shown in Fig.. This will provide a significant increase in the gain, enabling an electronic switch, for example, to be controlled by quite low sound levels. … [Read more...]
Transistors are current amplifiers. We sometimes need a voltage amplifier – for example, to boost the small signal from a microphone to an acceptable level. Although an op.amp provides the ideal solution, a simple one or two-transistor amplifier can be very useful, particularly if the quality of … [Read more...]
Basically siren on a police patrol car and an ambulance use electronic circuit connected to the DC current. When the switch is pressed, the siren sounds immediately come out.For those of you who own a car, or any motor you can also create a similar horn. Placement was also very practical. And if you … [Read more...]
In the picture above is a series of amplifiers are used, a booster amplifier class A common emitter (CE) transistor. Working point on the class A amplifier is set at a certain point that on the load line, so the phase output current is always flowing and the point Q located on the load line … [Read more...]
House plants in general often have a pretty hard time of it compared to their garden bound cousins, which seem to get more than their fair share of watering, even if their owner forgets, thanks to the British weather. With so many other things to think about, the first reminder that many people get … [Read more...]
Spice up your doorbell with this circuit which will produce random tones(17 million tones) every time you press your doorbell,Surely it will amaze your visitors. THE Random Doorbell circuit diagram shown in Fig. plays about 17 million tunes, thus employing about one component for every one million … [Read more...]