Strobe disk for a digital signal?

[hego]

I made a xtal oscilo (cd 4060) for 200hz. I divided this 4 times (cd 4013) and the ouput is at the end 50Hz (Europe).I use leds.

A regular neon bulb with a normal disk and the mains frec (sinus 50hz) work well, but not with my digital 50% duty cycle signal.

I add a simple low-pass filter and it seems something better.

¿There is a special "strobe disk" for digital "long" signal?

or.... maybe use a 100 or 200 hz?

Cheers.

 

[Pyramid]

The printed strobe discs are designed for 100 pulses/second as the neon bulb will illuminate on both the positive and negative peaks of the mains voltage.

You will get better results (less blurring) if the "on" pulse is shorter than 50% duty cycle.

 

[hego]

Ahhh.... I see sometimes 120Hz digital strobe for USA. I agree with the short light pulse. The 50% duty cycle is too looooooong!!!

Thank´s I will try the 100 Hz frec.

 

[hego]

Maybe like this?

How a turntable strobe works | eBay

 

[Osvaldo de Banfield]

A suggestion only. There is an IC that sources pulses of 50Hz directly from a 3.58MHz xtal. I'll see if I can find the part number.

 

[Osvaldo de Banfield]

I found.This is one of them:

https://www.elmelectronics.com/wp-content/uploads/2016/07/ELM440DS.pdf.

20mA of output current power directly the led. I don't know how cheap is it and it easiness to get it.

 

[Pyramid]

Maybe like this?

Use your existing circuit, minus one of the 4013 sections so you have a 100Hz square wave with 50% duty cycle. Add a 74123 one-shot circuit like the PDF attached. 1K5 with 1uFd should give you a 500µS pulse width (5% duty cycle). Making R1 smaller will decrease the on-time of the LED.

 

[hego]

Thank´s .

http://sudomod.com/forum/viewtopic.php?f=13&t=332

See the reset (400 hz) at the pin 10 (cd 4013) to short the duty cycle.

 

[Pyramid]

Thank´s .

120Hz LED Turntable Strobe in Altoids Tin - sudomod

See the reset (400 hz) at the pin 10 (cd 4013) to short the duty cycle.

Ahh! Very clever. No additional parts and you can go down the divider chain if you need a shorter on-time.

 

[hego]

I will try it (very easy) and will say something.

Cheers

 

[hego]

I tried it yet ... and now it works very fine, more better as the old neon bulb.

With the 400hz ( pin 2 from cd 4060) reset in the last 2xdivider (pin 4 2nd D-flip-flop) the final frequency is 100hz and the positive (flash-photo) duty cycle pulse is only 12.5%.Not 50%.The "photo" in any strobe disk is very clear.

I need anything.Very happy.

Thanks for yours recomandations.

Cheers