Help replacing an obsolete strobe light - Page 1
Forum section: electronics / beginners

author: jamessexycarrot
author_rank: Newbie
timestamp: October 09, 2024, 11:09:08 pm
content: Hey friends. My (future) father-in-law runs a small business in industrial balancing. He is not an EE whatsoever but has been making the attached circuit for a few decades now. The circuit has a motor that runs to balance the machines and a strobe light that flashes at a varying rate depending on the motor speed. The flashing helps the user identify the balancing/ motor speed.The part that has been obsoleted and needs replacement is the Excelitas Strobe Assembly with the Lite Pac trigger module FY505 + FX6A lamp bulb. There is no data sheet for these parts and the antiquated parts make finding a suitable replacement difficult.I looked at replacements online and the FYD-1100 serieshttps://www.excelitas.com/product/fyd-1100-series-lite-pac-trigger-moduleslooks the most similar and promising. The light requirements are rather low and I think modern LEDs are more than powerful enough nowadays (35 years laters). I was wondering if instead it might be better to connect a LED strobe light with an external power supply to replace these parts. I just don't know how I could connect a LED to the circuit in a way that it still flashes at the pace the analog trigger circuit demands.I am a total newbie and any advice is greatly appreciated!

author: Kim Christensen
author_rank: Super Contributor
timestamp: October 10, 2024, 12:37:45 am
content: You should be able to trigger a LED driver circuit with the opto output on J106-D and J106-C and eliminate the high voltage strobe section altogether. Don't really need the opto because the trigger could also be taken after K2 (on switch) which is before the opto. (All this assuming that the LED would be bright enough for all situations)Also, I noticed that D12 (1n4749) appears to be backwards on the schematic.

author: floobydust
author_rank: Super Contributor
timestamp: October 10, 2024, 01:58:46 am
content: The Lite-Pac FY-505 looks like just a trigger transformer and socket inside an enclosure. Drill out the rivet lol. EG&GFX-6Awas also used in other stroboscopes. Max. 500Hz (30,000 RPM) 5J/flash, average 7W, 7.9mm arc. Hard to estimate how bright the old tube is, for an LED equivalent.If you are sure the parts have croaked and it's not other parts such as the HV 525VDC power supply or SCR and associated capacitors, then I would look at converting it to LED. The electrolytic/tantalum capacitors like C8, C9, C1, C10, C11 might be getting long in the tooth as well. If I was servicing this, I would replace them as well. No idea what RPM this spins at or how big the light area is etc.It reminds me of automotive timing lights, you just have to set a decent LED-on pulse duration to match the xenon system and human eye. As well as getting the brightness decent- the two constraints.This schematic I think is from Silicon Chip magazine but shows a trigger circuit, pulse-stretcher and an LED array. I would say you need a say 12V power supply for the LED.Some question if white LED's are fast enough due to the phosphor, or are maybe the best colour to use.

author: jonpaul
author_rank: Super Contributor
timestamp: October 10, 2024, 05:54:16 am
content: 1960s GenRad/IET/General Radio Strobotac.WE have 3..6 of them.https://www.ietlabs.com/1531.htmlUsed on epay ~ $35...150.Jon

author: Poroit
author_rank: Frequent Contributor
timestamp: October 10, 2024, 09:02:34 am
content: G'day James,If your future Father in Law wants a dowry for his daughter you could consider something from Monarch Instruments.We used to sell and service these in Oz and always found them to be good quality.https://monarchinstrument.com/collections/nova-strobe-portable-stroboscopes?srsltid=AfmBOoph76OSRoIMJTcC4Z5H3EZbDv8RMe25D3EUVS0oZTtFJZZrj26E