Can a Microcontroller Replace a 555 Timer for a Low Frequency Flasher?

  • Thread starter Thread starter funnyguy
  • Start date Start date
  • Tags Tags
    Frequency Timer
AI Thread Summary
Using a microcontroller instead of a 555 timer for a low frequency flasher can provide greater flexibility in timing and duty cycle adjustments, potentially making it more cost-effective. Concerns about the cost of resistors and capacitors for achieving low frequencies may be unfounded, as they are generally inexpensive. Alternatives like a Wien bridge oscillator or a PWM signal for motor control were also suggested. The discussion highlights the importance of considering various timing solutions based on project needs. Ultimately, the choice between a microcontroller, a 555 timer, or other options will depend on specific requirements and available resources.
funnyguy
Messages
16
Reaction score
0
I want to build a low frequency, uneven cycle flasher somewhere around 10 seconds on, 5 seconds off. I planned on using a 555 timer and a MOSFET to drive my load, a small DC motor. Are there any other suggestions for something at low frequency? I'm just concerned at the R and C values needed for such low frequency as I might be able to buy a cheaper timer already assembled.

Thanks.
 
Engineering news on Phys.org
funnyguy said:
I want to build a low frequency, uneven cycle flasher somewhere around 10 seconds on, 5 seconds off. I planned on using a 555 timer and a MOSFET to drive my load, a small DC motor. Are there any other suggestions for something at low frequency? I'm just concerned at the R and C values needed for such low frequency as I might be able to buy a cheaper timer already assembled.

Thanks.

Do you expect that since you need such timing control for your 555 that "the R and C values needed" will be expensive? What is the cost of one resistor and one capacitor combined?

A cheaper timer might be constructed by placing a gerbil on a rotary treadmill. You could mount a contactor near the circumference to energise a microswitch each revolution. You'd need to teach the gerbil the correct timing, and also feed him or her, so it might be cheaper to stick with the 555 timer.

Cheers,
Bobbywhy
 
I believe what bobbywhy is saying, is that one R and C probably aren't going to cost you that much.

Use Mouser.com to find some L and C with $ values.
http://www.mouser.com/Passive-Components/Capacitors/_/N-5g7r/
http://www.mouser.com/Passive-Components/Inductors/_/N-5gb4/ Also, you could try using an oscillator. I would suggest a Wien bridge oscillator.
http://en.wikipedia.org/wiki/Wien_bridge_oscillator

That way, you would buy 2 R and 2C instead of one C and one L

You would have to change the duty cycle of the Wien Bridge oscillator. I am trying to find the circuit for that...
 
Last edited by a moderator:
Well, I didn't think they would, but I think the original documentation and formulas I had misled me. Originally, I looked at the calculations and thought that even with R values in the 100 kohm ranges I would need very large $5+ capacitors to make the high time what I needed. I see now that even with 7.5k and a 1mF cap I'll be in the range I need.
 


I would suggest considering using a microcontroller instead of a 555 timer for your low frequency flasher. This would allow for more flexibility in adjusting the timing and duty cycle, and may also be more cost-effective in the long run. Additionally, you could potentially use a pulse width modulation (PWM) signal to control the speed of the DC motor, rather than using a MOSFET. This would also give you more control over the motor's speed. Alternatively, you could consider using a different type of timer, such as a 555 timer with an adjustable resistor, or a 555 timer with a potentiometer, to achieve your desired frequency. Ultimately, the best approach will depend on your specific project requirements and resources.
 
Hi all I have some confusion about piezoelectrical sensors combination. If i have three acoustic piezoelectrical sensors (with same receive sensitivity in dB ref V/1uPa) placed at specific distance, these sensors receive acoustic signal from a sound source placed at far field distance (Plane Wave) and from broadside. I receive output of these sensors through individual preamplifiers, add them through hardware like summer circuit adder or in software after digitization and in this way got an...
I have recently moved into a new (rather ancient) house and had a few trips of my Residual Current breaker. I dug out my old Socket tester which tell me the three pins are correct. But then the Red warning light tells me my socket(s) fail the loop test. I never had this before but my last house had an overhead supply with no Earth from the company. The tester said "get this checked" and the man said the (high but not ridiculous) earth resistance was acceptable. I stuck a new copper earth...
I am not an electrical engineering student, but a lowly apprentice electrician. I learn both on the job and also take classes for my apprenticeship. I recently wired my first transformer and I understand that the neutral and ground are bonded together in the transformer or in the service. What I don't understand is, if the neutral is a current carrying conductor, which is then bonded to the ground conductor, why does current only flow back to its source and not on the ground path...
Back
Top