Miniature Generator for DIY

This generator allows you to obtain a logic signal with discrete variable frequency from 0.5 Hz to 300 kHz and with the amplitude of 5V. Schematic diagram of the generator (Fig. 1) is very simple, it uses a minimum of passive components and only two integrated circuits. Power supply 9V will yield with integral stabilizer DA1, connected to a miniature 9 V battery.

The heart of the miniature generator is a Schmidt trigger DD1.1, which, together with R1 and C1 form a flip-flop, built on the classical scheme. The difference frequencies produced by multivibrator is determined by the appropriate number of connecting all capacitors, resistors and switches. The signals at points V1 - V5 can be changed by using a different set of breaks or connections in the circuit lines with SAl switches - SA5. The two tables in Figure 2 and Figure 3 clearly reflect the dependence of the frequency on the output device of the position of these switches.

The generator requires little or no adjustment. It is only necessary to choose carefully the capacitors C2, C3, C5. It is better if tantalum capacitors are installed in their place. DA1 78L050 chips can be replaced or stabilizer KP142EH5A KR142EN5V voltage. As set inverting logic gates with Schmitt threshold applicable K555TL2 chip. BTW, you can select the miniature alternator at Banggood. Besides, you can easily get other electrical accessories (e.g. eyeglass magnifier) there with high quality and reasonable prices.