Free electronic circuit design and schematic diagram
WARNING: Don’t touch the circuit when plugged to the mains supply, this will cause a lethal electrical shock since it’s not isolated from the mains supply. A column of 10 white LEDs is illuminated by this circuit. The flicker is prevented by 10u capacitor and reduced by 100R resistor.
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While keeping the oscillator frequency relatively stable, this 555 based PWM controller features almost 0% to 100% pulse width regulation using the 100k variable resistor. To give a frequency range from about 170Hz to 200Hz , the frequency is dependent on the 100k pot and 100n. You can see the charging and discharging of the 100n cap is done through […]
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We can using this circuit to make the LEDs blink in a random pattern according to the slight differences in the three Schmitt Trigger oscillators. The CD4511 is BCD to 7 segment Driver, so the pattern of the led is actually the come from seven segment representation. Arrange the LEDs to be far from seven segment pattern if you want […]
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The TPS2390 and TPS2391 integrated circuits are hot swap power managers. These devices are optimized for use in nominal -48-V system. These devices are build with supply voltages ranges up to -80 V. These devices also rated to withstand spikes to -100 V. They can be used to enable live insertion of plug-in cards and modules in powered systems in […]
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The HYM1422 is an integrated 2.7V to 12V hot swap controller. This device allows a board to be safely inserted and removed from live backplanes. This is achieved using a pass FET with a current control loop that using a sense resistor, we can monitor the input current. The board supply voltage can be ramped up at a programmable rate […]
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We can make a very simple battery monitor using a dual-colour LED and a few additional components. When the red and green LEDs are illuminated, the LED produces orange. The following battery monitor circuit turns on the red LED below 10.5v. The green LED illuminates above 11.6v. The orange LED illuminates between 10.5v and 11.6v. This simple battery monitor circuit […]
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When audio is detected, the output is push-pull and consumes less than 3mA (with no signal) but drives the earpiece to a very loud level. It’s extremely difficult to set up because the whole circuit is DC coupled. Basically you don’t know where to start with the biasing. 8k2 between the emitter of the first transistor and 0v rail and […]
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