- Reaction score
- 4,338
I don't remember a 12v driver/transformer in any of the other sketch's, is it supplying 12v to just that one bulb or all of them?
Discuss Flashing LEDs when fan and lights off in the UK Electrical Forum area at ElectriciansForums.net
See post #33. Supplying just that bulb is my understanding. It was rather hidden amongst all the dialogue and explains why the halogen is not itself an adequate 'snubber'.I don't remember a 12v driver/transformer in any of the other sketch's, is it supplying 12v to just that one bulb or all of them?
I am still fascinated by this from post #21.As soon as I disconnect the timer SL the flickering stops.
I suspect that the electronic circuit in the manrose 1351 timer is acting as a dc voltage source circa 14V at its SL output. Tomorrow I will draw you a sketch of what I think the innards of the 1351 looks like. This small voltage current source is sufficient to light the low wattage LEDs dimly. Being dc the snubbers are ineffective since they are a series capcitor -resistor combo.
What we need is a voltage dependent way of isolating the SL output on the 1351 from the conductor going back to the SL on the connector strip to which the LEDs are connected. A zener diode is a possible way. Please would you obtain a few - say 5 to 10 - of these 24V Zener diodes. Here is a link to Rapid Electronics website but using the Amazon and search for 'BZX85C24' you will probably find some of them:
Vishay BZX85C24 24V 1.3W Zener Diode - https://www.rapidonline.com/vishay-bzx85c24-24v-1-3w-zener-diode-47-3088
When you have them you will another connector strip to mount either one or two of these Zener diodes in series with the SL just as it connectes to the SL terminal on the Manrose 1351 timer. I will show you how in a picture once you have the Zener diodes.
Note well: Just because they are 25 V Zeners their leads are at mains voltage so they will need insulating and and enclosure.
See my sketch attached.
I have the same unit to control my shower fan, it switches two independent LED GU10's in the shower cubicle without any flickering, but then I did wire it in accordance with the wiring diagram in post 7 between the SL and N into the Manrose unit after the switch.
I think that's the problem, the OP's fan has its own timer originally he had both the Manrose unit and the timer on the fan operating, did advise him to disconnect the fan timer, but it may need to be by passed.Nice thinking. It will be interesting to see where this goes. Seems like it is definitely linked to the fan somehow.
Thank you so much Marconi for that.
I turned up this ‘open up’ of a manrose timer fan.
I'll try and open a spare tomorrow and get back to you, thanks, Mark.Hi Clanky
If you haven't given up already (and by the 70th post perfectly understandable) could you take a pic of the insides of the Manrose 1351 timer and post it here. I believe you bought a second one in case the first was faulty (which it wasn't)?
PS from the pic below, it may be slightly tricky to get into it - don't break anything, I'd rather you left it!
View attachment 110023
Avo Mk8 - i have taken Mr Marconi's advice and ordered Zener diodes - will fit them when they arrive.Hi Clanky
Do take the advice of Mr Marconi, who is a very knowledgeable and well respected member of this forum, and buy the zener diodes he suggests (cheaper than snubbers if you find the right supplier).
All the evidence suggests this will solve the problem!
Good afternoon Marconi, when I get the diodes what type of enclosure do I pit them in - a small wago box with heat shrink on diode tails into wago connector/chocolate block?I drew the zener diodes connected the wrong way round in my first post. To block the +14V they need to be as in the sketch attached.
Thank you - I will try the double choc bloc option, I think there will be room. I wasn't sure if there would be any heat generated by the diode.Hi
Apologies for chiming in on this.
It occurred to me if you are using the Manrose 1351 back box supplied with it, that's an enclosure that you could use right away!
Probably a good idea to sleeve the leads of the diode, though doesn't have to be heat-shrink!
You could put the banded end of the diode in the SL terminal of the Manrose, and stick a single choc block, or 2 hole Wago on the other end of the diode, and add the wire that was previously in the SL terminal.
Or a more elegant and robust method (for the diode) would be to put the diode across the terminals of a twin choc block, and then wire that to the SL terminal and the switch cable.
That all assumes there is enough room amongst the wiring already in there!View attachment 110082
No heat. Good luck!Thank you - I will try the double choc bloc option, I think there will be room. I wasn't sure if there would be any heat generated by the diode.
Many thanks Mark.
Reply to Flashing LEDs when fan and lights off in the UK Electrical Forum area at ElectriciansForums.net
We get it, advertisements are annoying!
Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.