Category: Electronic Measurement and Tester Circuit

Digital counters are frequently needed in all kinds of counting circuits, test gear, sequential displays, timers, etc for up to ten outputs (exclusive and independent), or 16 at the most. But the problem arises when it comes to using more than these many outputs. In such a case, the 4017-based CMOS counter can be put to use as a 100-stage counter. The circuit configuration uses a dozen 4017 counter ICs. IC12 sends clock pulses to IC11 at one-tenth of its input frequency, which in turn allows Qa through Qj to…

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The versatile IC timer 555 has yet another application as an analog frequency meter. By making use of a 556 integrated circuit, which has two 555 timers in a single package, an over-range indicator can be economically added to the meter. Circuit Description of Analogue Frequency Meter with Over-range Indicator When this meter is switched to the 50Hz range, any input frequency from near DC to 50 Hz produces a correct panel meter reading, i.e. a frequency of 42 Hz produces a meter reading of 42 microamperes. However, the analog…

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While servicing gadgets, changes often occur when you feel the necessity of checking a defective resistor, shorted diode, transistor, or capacitor in a circuit. Didn’t you desire that all could have been done without switching on the gadget and without de-soldering and extracting the components? Here is a simple and effective remedy called In-circuit Ohm-meter. All you need in two transistors are a few resistors. Circuit description of In-circuit ohm-meter When an emf of about 1.5 volts is applied across the emitter-base junction of a germanium transistor, an emf of…

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