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LED Flasher Relay Flash Rate

Discussion in 'LEDs and Optoelectronics' started by schemer, Aug 10, 2012.

  1. schemer

    schemer

    27
    0
    Aug 10, 2012
    Hi everybody,
    I am new here and this is my first post. I am not a student but probably should be. :) I thought I was pretty smart but the more I read the less I know it seems. :confused: I have some LED flasher relays that I thought would have been IC based for some reason and have a few questions about them. The relay is a CF13JL-02 and I put one on my motorcycle but it flashes too fast at about 180 flashes per minute as opposed to the 90-120 fpm they are usually advertised at.The flash rate also changes with the voltage changes. The bike has a regulator so that isn't the main problem, I just noticed that when testing with the bike not running (at 12.6 volts) and when running (13.8 volts) it goes way faster than 180 when running.
    So I take the flasher apart and think I can mod it. It has 2 PNP transistors, 6 resistors, 1 diode, 1 capacitor, and a simple SPST relay. After 3 days of toying around I looked at 20 different schematic making programs and still don't have a schematic. :( I was thinking an easy capacitor swap could fix this but the local RatShack doesn't have anything even close to the 15v 67uf cap that I wanted to up the value on. My concern is that I don't understand how the resistors are really being used and they may be the answer to the puzzle. I played with a LM317T to regulate the voltage but it seems like it would be hard to incorporate into the package.
    Anybody ever have one of these apart or can help guide me into a mod to fix the problem?
    Thanks,
    schemer
     
  2. CocaCola

    CocaCola

    3,635
    5
    Apr 7, 2012
    Pictures?
     
  3. schemer

    schemer

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    Aug 10, 2012
    Here you go...
    Thanks

    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
     
  4. john monks

    john monks

    693
    1
    Mar 9, 2012
    If I read this right the capacitor is 47uF.
    You can.t find a 100uF that will fit in the space?
    Short of that the only thing I could suggest is to try increasing the value of the resistor one by one by about 50% starting with the 15kohm or the largest one.
     
  5. schemer

    schemer

    27
    0
    Aug 10, 2012
    John,
    That was my first thought, to change the cap. Yes it is a 47uf cap. I thought I had all kinds of caps but they are all the wrong voltages for pc repair etc. I may have one in an axial but was thinking it needed to be polarized in this circuit. Radio Shack didn't have them local. I can order some no problem. Just wanted to make sure I wasn't thinking wrong about it being the cap as the fix. What confused me was the layout and the wide differences in resistor values, and trying to make a schematic to better understand it. It has 6 resistors of the following values:

    2 - 1.2k
    1 - 12k
    1 - 15k
    1 - 18k
    1 - 100 ohm

    I will see if I can cannibalize one from somewhere and then order some caps. I didn't quite know how to figure the math on the Time as it was hard to get past the transistors and their use of the resistors. I did find TinyCad to be one of the easier schematic programs so far although I only used it a few minutes. Got a recommendation on a good tool for learning like Eagle, Diptrace, Kicad etc? I have them all and need to focus and learn just one as otherwise my head will likely explode. :D
    Thanks,
    schemer

    p.s. I have plenty of resistors and those are readily available.
     
    Last edited: Aug 10, 2012
  6. john monks

    john monks

    693
    1
    Mar 9, 2012
    There is no reason why the capacitor needs to be polarized but I doubt that you can find one small enough to fit.
    Certainly you can use an axial leaded capacitor.
    Now that I see your values I would think that if you increased the 18k and the 15k you would be in luck.
    Most such timing resistors are the larger ones.
    A schematic would certainly answer the question.
     
  7. CocaCola

    CocaCola

    3,635
    5
    Apr 7, 2012
    Using higher voltages is fine...

    As for a learning tool Eagle has much of the hobbyist market so it might be a good starting point, although it's always annoyed me ;)
     
  8. schemer

    schemer

    27
    0
    Aug 10, 2012
    Thanks John,
    I will look at my axial capacitors again and give one a try if I can finagle one in, if only for a test. Knowing the timing resistors are the larger ones helps too. I searched for a schematic and couldn't find one so I am trying to make one. Too bad it would most likely be my "first" schematic and not very pretty and probably not "very" accurate. Its harder than I thought making sense from a circuit board view into a schematic view. I will keep working on a schematic...
    Thanks again,
    schemer
     
  9. schemer

    schemer

    27
    0
    Aug 10, 2012
    I meant all the wrong values. I am aware you can use a higher voltage. :) So you think Eagle is the way to go? What do you really use? My initial problem is trying to find the correct component in the library to match mine and then I start trying to create a component. Tried that in KiCad...Not an easy thing for if you are in a hurry.

    Thanks,
    Schemer
     
    Last edited: Aug 10, 2012
  10. CocaCola

    CocaCola

    3,635
    5
    Apr 7, 2012
    If you just want to determine if it effects the timing like you hope, actual value is not that important...

    It's what you will fine most hobbyist use because it's very affordable and does the job well... And thus there is a lot of community support for the product...

    My primary design software is the Proteus Suite... But, I'm not exclusive to that since I do contract work for others, I am sometimes forced to work with other software suites if and when the client has existing work done in them...
     
  11. CocaCola

    CocaCola

    3,635
    5
    Apr 7, 2012
    May I also suggest that if you are into reverse engineering and existing design you get your Photoshop skills in hand, with good photos and layers it makes things easier...

    This is just and example with your photos, with more care and even depopulation of the board for the photos you can really get some good pictures to work from...

    [​IMG]
     

    Attached Files:

  12. schemer

    schemer

    27
    0
    Aug 10, 2012
    Thanks CocaCola and John for the help...I am working on the schematic now but it will need some fine tuning. Don't laugh, it's my first one and I am using TinyCad. Seems like the most user friendly so far...Please point out any wrong symbols etc. ;)
    schemer

    [​IMG]
     
  13. schemer

    schemer

    27
    0
    Aug 10, 2012
    Thanks CocaCola, I was doing it the hard way but the thought did cross my mind. I was using an LED flashlight and looking thru the pcb. I think I can do a little photoshop stuff. :D
    Thanks again,
    schemer
     
  14. john monks

    john monks

    693
    1
    Mar 9, 2012
    Sorry, can't be correct but I'm looking for the errors.
    Can you get the numbers off the transistors and the relay?
     
    Last edited: Aug 11, 2012
  15. schemer

    schemer

    27
    0
    Aug 10, 2012
    Sure John,
    The transistors are both pnp and are MPS 2907a and the relay is a HF32F-G.
    Thanks for the help,
    schemer
     
  16. john monks

    john monks

    693
    1
    Mar 9, 2012
    Are you sure the relay is a CF13JL-02 ?
    The relay you have a picture of seems to be different.
    Yours shows the emitters of PNP transistors at ground and one output pin of the relay at ground. The relay should be switching 12 volts onto your turn lights.
    Can you check again.
     
  17. schemer

    schemer

    27
    0
    Aug 10, 2012
    Hi John,
    Well, the relay looks like a JZC32F and the reason I said it was a CF13JL-02 was because I was looking for a spec sheet and then I guess I found some info on suitable crossovers to other part numbers. I have pages of notes and sometimes they can get confusing. But the CF13JL-02 should be the same. Now for the picture of the relay that is a different thing. I just picked from the available choices a SPST relay that I assumed is the same basic relay. The transistors on the other hand are what I said, but I am no expert so I may have the leads messed up. I will look at a spec sheet and try to clarify the whole schematic and try to improve it. Probably best for in the morning with a clear head. I will double check my interpretation of the connections to the schematic I made. I told you it was my first one. :D
    Thanks,
    schemer

    p.s. The contact arrangement on the relay is a FORM 1A so it should only have 4 connections.
    http://www.datasheetcatalog.org/datasheets2/69/69039_1.pdf
     
    Last edited: Aug 11, 2012
  18. john monks

    john monks

    693
    1
    Mar 9, 2012
    Your flasher looks like the 12 volt power pins are the reverse of the CF13JL-02.
    That what leads me to believe there is a mistake.
    One thing you could do is look up the flasher for your make and model of your motorcycle.
     
    Last edited: Aug 11, 2012
  19. schemer

    schemer

    27
    0
    Aug 10, 2012
    Could be my being a noob at making a schematic. :eek: I may have to disassemble and ruin one of these to see what's really going on. Or I could send you one (as I have spares) and you could probably decipher it real quick. I also need to remove the diode as on a closer look I can't identify it and it looks like a zener. As far as looking one up the bike has no original signals and an after market dual sport harness in on it. The relay I had on there was a thermal type but I added a safety piezo buzzer and the thermal flasher sent feedback thru the buzzer as it heated up the filament before it beeped when the lights flashed. I could buy a solid state flasher for $23.95 plus shipping but what fun is that? :) That may be my next project. ;)
    Thanks,
    schemer

    p.s. The relay in the flasher is in fact a JZC32F as I can read it but just barely.

    p.s.s. I think I may have the relay in the schematic in the wrong position. Will think on it in the morning and adjust as needed.
     
    Last edited: Aug 11, 2012
  20. KJ6EAD

    KJ6EAD

    1,114
    157
    Aug 13, 2011
    If you can speed it up, you can slow it down; an adjunct to John's post #4.

    Another trick you can use to identify the timing resistor is to add another resistor in parallel which should speed the timing up noticeably when connected to the correct resistor. The advantage is that you can do this test without desoldering anything. Just attach a resistor (~33k, exact value not critical) via two hook or alligator test leads across the 18k, 15k and 12k resistors on the board one by one until you find the one that speeds up the timing. Obviously, you have to power the circuit with 12VDC and monitor the output with a test light.

    Once you've identified the timing resistor, you can snip one lead to open the circuit and provide an attachment point for testing higher value substitutions.
     
    Last edited: Aug 11, 2012
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