Hi
can the MK107 kit be used doubling the amount of L.E.D’s without overloading the chip?
I wish to use 2 led’s per o/p with an extra resistor in series!
Cheers!
If you put the leds in series, it will work fine.
Thanks for that. I was thinking paralell not series but that makes sense, but what would be the maximum amount of leds per o/p I’m assuming if 12v then in theory 5 leds assuming no current overload! Thanks again for your time!
Current is not an issue as it stays the same.
Number of leds depends on voltage drop over the led (colour).
Just one more question. If the suppy voltage is say 12vdc what is the voltage going to be at the pin o/p’s for the leds so I can decide how many leds I can use per pin o/p. I’m making the assumption that the o/p voltage will follow the supply voltage?
Voltage at pins is supply minus one diode drop.
Thanks for the info! will try out and let you know if the theory and practical work out similar!
Hi Have now built the circuit but it only works spasmodically and not due to bad joints, it will decide to work for up to 5-10 secs.
Voltage is from a stable 12v dc supply current is a nominal 8mA
Votage when not functioning on 555 pins is a follows
Pin 1 =0v
Pin 2,6 = 5.5v-7.2v variable with pot
Pin 3 = 10.7v also sharp negative/positive pulses frequency variable with pot*
Pin 4,8 = 11.3v
Pin 5 = 4.5v-6.5v fluctuating
Pin 7 = 5.5v-7.2v variable with pot
4015 voltages
Pin 1,9 = 10.7*
Pin 2,3,4,5,10,11,12,13,15 = 0v
Pin 6,14 =0v
Pin 7 = 0v
Pin 16 = 11.3v
When Sw2 pressed down current increases to 12mA but no activation of chip same with Sw1
Is there any thing from this that will offer a clue as to the problem, it may be that I can’t see the wood for the trees as they say!
Differences to original cct is that I have 4 leds in each o/p with a 560 ohm res in series
Check with leds mounted according to the instructions. If this works fine, kit is OK, problem is caused by modification.
Oops! 
On further checking I had omitted R11 now fitted that problem solved. 
But I still have further issue. How can I make the circuit operate automatically without the use of Sw1 & Sw2 when the supply voltage is applied to it only, via another timer cct! 
But I still have further issue. How can I make the circuit operate automatically without the use of Sw1 & Sw2 when the supply voltage is applied to it only, via another timer cct! [/quote]
I’m sure there is a way using either an electronic device which could act as a momentary switch at power up. I tried electrolytic caps which sort of work but then when charged cause a problem. Is there a way the 4015 chip could be reconfigured to do this??
Mechanically there are no relays out there that I could find to replace the switchs unless you know of a manufacturer that makes a 4+ way momentary contact one?
I managed to configure a 556 chip to do this, In the A section using a time of aprox 0.05mS(470 Ohm x 0.1mF) to get a pulse from pin 5 to activate Sw1 in the MK107 at the same time trigger section B to give a similar pulse from pin 9 to Sw2 via 470ohm res in series with a 220mF cap to give a delay long enough before the charging cap reached a reset voltage. This worked for the purposes I need it for! 
to start without pressing program button just add a dc cap across the switch…1mfd 16v…will start in chase mode 
If I remember I did try this but it didn’t work as I wanted hence the alternate way I went, but thanks for your suggestion!
hi there…just bought my one yesterday up loading on to youtube tonight when it gets dark [ light house that is]…under user name 22wabbits22 …velleman chaser lighthouse mod …all worked ok on my one but i have to press the progam button a bit longer to change prog …all the best with your one…paul
Hmm I tried all of the options mentioned and cannot get it to trigger on when powered up. Blotto, can you clarify your solution? Did you jump from pin 5 on the 555 with a 470 ohm resister to the SW1? And, then jump from pin 9 on the shift register with a 470 ohm resister in series with a 220uF cap to the SW2? Which pins on the SW1 and SW2 did you connect to?
Thanks for any help.
[quote=“chinablue”]Hmm I tried all of the options mentioned and cannot get it to trigger on when powered up. Blotto, can you clarify your solution? Did you jump from pin 5 on the 555 with a 470 ohm resister to the SW1? And, then jump from pin 9 on the shift register with a 470 ohm resister in series with a 220uF cap to the SW2? Which pins on the SW1 and SW2 did you connect to?
Thanks for any help.[/quote]
Hi
Sorry about the delay I retired a couple years ago and that project I finished in Dec 10 it was going to be used in India (I’ve not heard since whether it was a success or not, as you may know what works in the workshop may not work in the real world due to a variety of factors)
I cannot remember how I connected the 556 up to the unit, but I’m sure that the outputs would have connected to the active side of the switches