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Sign Modulator - Class Project

The output of the LM311 must be wired to Vcc through a pullup resistor of 2 kΩ. The EMIT OUT pin must be wired to ground. Two pins of the timer 555 must be wired: RST (pin 4 to VCC) and ... CONT (...
Antonio51's user avatar
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1 vote

NE555 + CD4017 Airplane Strobe Light with LDR

Other answers have noted the problem, but I'd suggest an alternative solution: have the right side of the LDR connect to Q8 of the 4017 rather than VDD. That would ensure that no matter where during ...
supercat's user avatar
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6 votes

NE555 + CD4017 Airplane Strobe Light with LDR

The LED is getting stuck on because you're not also resetting the CD4017.
Dave Tweed's user avatar
  • 170k
4 votes

NE555 + CD4017 Airplane Strobe Light with LDR

There should be a pull-up resistor (say 10k) between the 555's Reset (pin 4) and Vcc. Also add a decoupling capacitor (4.7uF) between Vcc and ground close to the 555's pins 1 and 8. You need to hold ...
user350400's user avatar
1 vote

Motor Driver Project using 555 Timer PWM + 4N25 + 2N7000

Power source: two 12V dc, 450mA power supplies Oh, that's interesting! It means your supply is inherently supplying less current than your motor might be able to sink. This is relevant in this ...
Marcus Müller's user avatar
1 vote

How to boost the output voltage of my 555 timer design?

The circuit with the 555 cannot apply more voltage than the power supply to the piezo buzzer. So it will be less loud than if you connect it directly across the battery. The circuit you show would ...
Spehro Pefhany's user avatar
0 votes

switching off 555 timer with trigger button

Here is an idea that manipulates the switching threshold point, by the D-type flip-flop, to terminate the timing cycle early. D1 is used as a low reverse-leakage diode with 2.2 V forward drop. Circuit ...
DM2236's user avatar
  • 201
2 votes

555 delay timer before powering PCB with 5 V

That's not how a 555 timer works at all. Your description of the circuit is incorrect and the circuit itself is incorrect. The 51K resistor does not go to ground as you say, it goes to the trigger ...
GodJihyo's user avatar
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0 votes

Monostable "One shot" 555. Longer trigger than T (output pulse width) eliminator

This can also be built with 2 transistors, a capacitor and a few resistors. An example a bit down in the forums here (only a breadboard overview, note one superfluos resistor, and the rightmost ...
wrOngplanet's user avatar

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