Maplin Universal Timer Kit

[rodshaw]

Has anyone used the Maplin timer kit, as shown here: http://www.maplin.co.uk/universal-timer-kit-3315 ?

 

I need something to turn my Seuthe smoking chimney unit on for a preset time, e.g. 3 minutes or so, and this looks like a possible option. The idea is that the public would be able to turn it on at shows (if the layout ever gets to one), and it would turn itself off without me having to be constantly checking.

 

I assume that the built-in relay could replace the on-off switch currently wired to the smoke unit.

 

Any comments?

[Stubby47]

With a Maplin store having opened within 500 yrds of my house only this month, a quick visit for research purposes did highlight this item and several others in a similar vein.

 

Whilst having no idea if your theory would work, I too will be interested in the replies.

 

Stu

[noiseboy72]

For something this simple, a 555 timer and half a dozen components will do what you need. Google 555 and timer for a suitable circuit.

[ELTEL]

Has anyone used the Maplin timer kit, as shown here: http://www.maplin.co...-timer-kit-3315 ?

 

I need something to turn my Seuthe smoking chimney unit on for a preset time, e.g. 3 minutes or so, and this looks like a possible option. The idea is that the public would be able to turn it on at shows (if the layout ever gets to one), and it would turn itself off without me having to be constantly checking.

 

I assume that the built-in relay could replace the on-off switch currently wired to the smoke unit.

 

Any comments?

 

 

Looking at the Maplin spec it seems that it will control up to 2A (does not state if that is constant) You will need to check that the Seuthe unit is well below that figure. From memory I think they draw about 1A so it should work.

 

Eltel

[Gordon H]

For something this simple, a 555 timer and half a dozen components will do what you need. Google 555 and timer for a suitable circuit.

That appears to be exactly what the Maplin (Velleman) kit is.

The 2A rating is purely down to the relay used, so it is a continuous figure.

[rodshaw]

That appears to be exactly what the Maplin (Velleman) kit is.

 

Yes, that's what I thought, I have a circuit diagram for something similar, but it hardly seems worth the bother buying the individual components.

[gwrman]

Hi, would this be any good http://www.ebay.co.uk/itm/Adjustable-Timer-Relay-Kit-2-5sec-60-sec-EM120-/160738471823?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item256cc26f8f

 

Nigel 8)

[rodshaw]

Hi, would this be any good http://www.ebay.co.u...=item256cc26f8f

 

Nigel 8)

Looks similar but costs more.

[rodshaw]

I've started to assemble this Maplin timer kit and have been thinking about how to test it.

 

The instructions say that it needs connecting to a 12V DC regulated power supply. Would anyone know whether the track output from a Gaugemaster controller is regulated? I'm thinking that if I turned the control knob up to full, it should be producing about 12V DC, but I don't want to fry the timer unit. There again I don't want to buy another power supply if I can use the spare Gaugemaster output.

[Brian]

Hi

The GM output is not regulated.

'Regulated' means the supply volts are constant regardless of the load placed upon the supply (from no load up to its maximum rating of course).

Non regulated 12 volt supplies can deliver 14 to 16 volts without load or little load. Then some can dropping to below 10 volts as the loading gets towards the supplies maximum.

 

For testing, I personally would use the controller and ensure the output polarity is correct and the speed setting is not above 3/4 full on. A dc volt meter connected across the controllers output terminals would be more advisable.

 

Edit to add.. If the supply is non regulated the timers timing cycle will drift with different voltage inputs. Hence the Regulated PSU recommendation.

[rodshaw]

Thanks Brian.

 

The instructions for the timer also say it needs 300mA, whereas I think Gaugemaster controllers produce about 1 amp, so presumably this could cause problems too?

[cpman46]

Rod

No problems regarding current. As long as your Gaugemaster can supply 300mA, which it can quite comfortably, it will run the timer with the caveats as suggested by Brian. The only problem you would have with the Gaugemaster is if you tried to exceed its rated output by drawing more current than it can give. In those circumstances the built in current limit would come into play and shut off the output. As Brian indicated use a multimeter to measure the volts as you increase the output. This will ensure you don't overload the timer input voltage. For long term use a suitable regulated 12V dc supply should be used.

Regards

Mike

[rodshaw]

I am now the proud owner of a 12V DC regulated supply, from Maplins, and have finished assembling the timer kit. Tried it out - nothing, not a sausage. But then I discovered one of the joints under the 555 timer, which I'd oh so carefully soldered and thought I'd tested, was now loose. So back out with the soldering iron tomorrow...

[rodshaw]

I must have done something wrong, everything on this Maplin timer kit looks to be soldered up properly but I just can't get it to work. The relay moved and the LED came on the first couple of times I tried it, but then nothing, so I assume something has come loose or burnt out, though I can see no signs. The 555 timer also gets very hot. I quite possibly connected the power leads the wrong way round at least once, and maybe this caused the problem.

 

To save messing about, as I'm no electronics expert, I decided to cut my losses and bought this off ebay:

 

http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=270910684908&ssPageName=ADME:L:OC:GB:3160

 

It's ready assembled and cheaper than the Maplin timer, even after adding the very reasonable postage. I was a bit wary of ordering something from Bulgaria, but it arrived within the week and it works a treat. The time delay is adjustable and it has in-built protection against the power leads being connected the wrong way round.

 

The same seller does various electronic devices for all sorts of applications, well worth a look.

 

Meanwhile...if anyone has any suggestions why the Maplin timer may not be working, I'd be interested to know, though I realise it's a bit of a long shot.

[cpman46]

Rod

If you inadvertantly connected the supply the wrong way round with no reverse polarity protection on board I would suggest you have definitely b******d the 555 as indicated by the device getting very hot. You could try replacing the 555 ensuring you connect your supply the right way round!

your Bulgarian replacement looks the same as the Maplin Kit except the pushbuttons are off board.

Regards

Mike

[rodshaw]

 

your Bulgarian replacement looks the same as the Maplin Kit except the pushbuttons are off board.

 

 

...yes, the components and connections do look similar - but it also has polarity protection! I know this works because, being the gung-ho type, I tried it. But thanks for the tip, I may try replacing the timer chip on the Maplin device so at least I have a spare unit.

[rodshaw]

Finally got it fixed. I don't know about anyone else but for me, August is a write-off as far as modelling goes. After coming back from holiday I'm really not in the mood for a few weeks.

 

Anyway - timer unit operated by a 12V regulated PSU which turns the smoking chimney on at the push of a button and switches it off after a preset time.

 

it's amazing how much wiring you need even for a small project like this - two wires to the PSU, two from a relay to the smoke unit circuit, two to the on pushbutton and two more to the off/override button. Not forgetting the separate wires from the Gaugemaster controller to the smoke unit.

 

But it works!

[Brian]

Finally got it fixed

.<Snip>

But it works!