All Questions
34
questions
2
votes
2
answers
224
views
How can I generate square pulses of the format shown in picture? The positive part should have smaller time scale
How can I generate pulses of this format? I need to generate a single pulse of 20V as a trigger pulse for performing a microscopy experiment( I couldn't manage to get a programmable function generator ...
- 31
0
votes
2
answers
194
views
Rising and Falling edge pulse alternative
I have a requirement to generate a 4 sec pulse when a switch is closed and another pulse when the switch is open with minimal (<10uA) to zero power consumption when the pulses are not being ...
- 33
1
vote
1
answer
410
views
How to generate a single pulse for certain milliseconds or second without microcontroller?
I'm using an IR sensor as an input and I want that when IR sensor (A) goes high, then a single 300-ms pulse is generated at (B), such that even if (A) stays high, it doesn't generate any other signal ...
- 15
0
votes
0
answers
183
views
Clock Generator with Variable Pulse Width Design Help
I'm working on a design that requires a clock generator with variable pulse width. The pulse width is controlled by a potentiometer, and the clock speed is controlled by another potentiometer. It's ...
- 43
0
votes
2
answers
296
views
Turn signal detector
I'm trying to figure out the simplest design possible. I want a video camera to activate on my truck when I activate either left or right turn signal. Each side mirror has its own camera. So basically ...
1
vote
4
answers
843
views
Pulse a 555 astable oscillator every second without an additional IC
I am developing a ranging device to help people with blindness. I need to pulse a 38 kHz Infrared LED every 1 second.
A 555 timer in astable mode generates the 38 kHz modulation. I'm currently using ...
- 47
0
votes
2
answers
2k
views
Converting latching switch to momentary output
I'm trying to get a latch switch to send a pulse for around 3 seconds or so. The pulse doesn't need to be pretty or precise. The circuit will be used to sound a buzzer when the switch is flipped on. ...
0
votes
1
answer
290
views
Astable 555 Timer how to create longer pulse at reset/beginning/turning on
I would like to build simple 555 based fan controller. The requirements are:
at start the controller generates one longer pulse (which can be configurable)
after one longer pulse it generates PWM ...
2
votes
2
answers
1k
views
How to get a single pulse for 10 milliseconds?
I am trying to get a single pulse of 10 milliseconds on the output of my 555 timer. I following is my schematic:
I am supplying 12 V for Vcc. The value of Resistor R and capacitor C is 100 ohms and ...
- 101
1
vote
2
answers
889
views
One shot pulse generator Low->High->Low even if button is still pressed?
I am trying to use a 555 IC to create a low-high-low pulse that will trigger only once and still go low even if the button continues to be pressed. This is the ...
- 13
1
vote
0
answers
249
views
555 timer unstable pulses
I'm using a 555 timer to drive the clock of my circuit.
However, even with capacitors from VCC to GND, and from Pin 5 to ground, I'm still getting this "bump" when the timer transitions from ...
- 11
1
vote
1
answer
259
views
How to limit pulse duration?
I'm trying to design automotive-oriented circuit to limit ignition pulse duration from OEM ECU to an aftermarket ECU plug-in device. The device expects +12v pulses no longer than 9ms, while the car in ...
- 25
3
votes
3
answers
2k
views
Generation of a shorter pulse based on trigger (similar to 555 as monostable)
I need to create a shorter pulse based on a trigger signal. Trigger signal has a duration between 1 to 10 ms and the desired output should be 0.5 ms.
To do the opposite (longer output pulse than ...
- 1,309
0
votes
1
answer
138
views
How to pull a normally floating pin to ground for 500ms when circuit powered on and circuit powered off [duplicate]
I need some help designing a circuit to pull a floating pin to ground for approx 500ms when the circuit is first powered on, then pulling it to ground again for another 500ms when powered is lost. The ...
- 3
1
vote
1
answer
2k
views
Power Latching Relay off/on in response to 12V ignition and 1 second ground pulse
I have the following sample schematic of a 12 volt automotive circuit to trigger about 60 seconds of power output to a latching relay on output pin 3 of the 555 Timer chip.
The schematic below is a ...
- 13