pegasus bridge Posted April 3, 2012 Report Share Posted April 3, 2012 (edited) after looking at another thread discussing a lamp dimmer - i stumbled across a couple of items on a large auction site that i thought might work ; so I bit the bullet and brought one - less than £12 delivered in 7 days from Hong Kong. its designed as a remote control / dimmer for LED lights. But it works on 12-24v with an output current of 8a (I am reliably informed by HW682!) should cover a magnet. I have set it up this morning and run it for 2 hours, turned it off and on a dozen times, run it at slow, fast and medium speeds - no sign of heating up! so at this stage it looks like a very good value remote control on/off and speed control for magnets or flappers. (this is all the testing i have done - but i will keep this updated as it gets some serious field use) I just thought i would share this with the good people of PW ps - a pic for now - but i have got a video of it all working to upload tonight. edit - pic of internals Edited April 4, 2012 by pegasus bridge Quote Link to comment Share on other sites More sharing options...
noxop666 Posted April 3, 2012 Report Share Posted April 3, 2012 was that of evilbay ? Quote Link to comment Share on other sites More sharing options...
steve_b_wales Posted April 3, 2012 Report Share Posted April 3, 2012 Sounds interesting. Quote Link to comment Share on other sites More sharing options...
Catweazle Posted April 3, 2012 Report Share Posted April 3, 2012 It looks interesting, although I would be a little concerned that it might get damaged running an inductive load like a motor. A spike suppressor of some kind across the motor connections might be worth investigating. Quote Link to comment Share on other sites More sharing options...
pegasus bridge Posted April 3, 2012 Author Report Share Posted April 3, 2012 (edited) was that of evilbay ? yes - plenty on there - search for 12v remote switch Sounds interesting. i thought it was worth a punt - i left it running and nipped out, still running, all seems fine so far. It looks interesting, although I would be a little concerned that it might get damaged running an inductive load like a motor. A spike suppressor of some kind across the motor connections might be worth investigating. cheers - what exactly is that? (my knowledge is pretty basic) i was thinking of an inline fast blow fuse - is that what you mean? Edited April 3, 2012 by pegasus bridge Quote Link to comment Share on other sites More sharing options...
Catweazle Posted April 3, 2012 Report Share Posted April 3, 2012 cheers - what exactly is that? (my knowledge is pretty basic) i was thinking of an inline fast blow fuse - is that what you mean? When an inductive load like a motor winding has the power supply interrupted the magnetic field collapses and induces a "reverse" voltage in the coils, google "back EMF". This voltage can be quite high and can damage semiconductors. The power can be interrupted by things like a bad contact on a motor brush. The back emf is sometimes called a "spike". Devices are available which can be connected across the motor connections or in series with the connections to filter the spikes out before they get back to the controller. Quote Link to comment Share on other sites More sharing options...
pegasus bridge Posted April 3, 2012 Author Report Share Posted April 3, 2012 When an inductive load like a motor winding has the power supply interrupted the magnetic field collapses and induces a "reverse" voltage in the coils, google "back EMF". This voltage can be quite high and can damage semiconductors. The power can be interrupted by things like a bad contact on a motor brush. The back emf is sometimes called a "spike". Devices are available which can be connected across the motor connections or in series with the connections to filter the spikes out before they get back to the controller. cheers - I'll look into that ; this is the video from this morning Quote Link to comment Share on other sites More sharing options...
TR1 Posted April 4, 2012 Report Share Posted April 4, 2012 What range can you get on the remote. I made a similar on/off device, bits from same source, reliable range up to about 20 metres. Quote Link to comment Share on other sites More sharing options...
pegasus bridge Posted April 4, 2012 Author Report Share Posted April 4, 2012 What range can you get on the remote. I made a similar on/off device, bits from same source, reliable range up to about 20 metres. i have not yet tried it past about 15 mtrs - i'm going to take it out at the weekend and try the distance in the field. Quote Link to comment Share on other sites More sharing options...
HW682 Posted April 4, 2012 Report Share Posted April 4, 2012 its designed as a remote control / dimmer for LED lights. But it works on 12-24v with an output current of 8a (I am reliably informed by HW682!) should cover a magnet. Just to cover myself if this goes belly up I said that the magnet current would almost certainly be less than 8A, but no guarantee that it would work reliably. It looks interesting, although I would be a little concerned that it might get damaged running an inductive load like a motor. A spike suppressor of some kind across the motor connections might be worth investigating. Good point. For the sake of 10p it might be worth adding a (flyback) diode across the output terminals. So far, looks like it was worth a punt. Quote Link to comment Share on other sites More sharing options...
pegasus bridge Posted April 4, 2012 Author Report Share Posted April 4, 2012 (edited) Just to cover myself if this goes belly up I said that the magnet current would almost certainly be less than 8A, but no guarantee that it would work reliably. i took that 'it will probably work' as a full belts and braces, lloyds backed, gold plated 5 year warranty of superior performance - I have run it again this afternoon in the shed for a couple of hours - still works fine, no heat - seems fine Good point. For the sake of 10p it might be worth adding a (flyback) diode across the output terminals. So far, looks like it was worth a punt. can you point me in the right direction with that - would it be possible to do this 'inside' the casing? how big is the diode? would the same apply to the other remote (the basic one for the flapper only?) also - would it be worth adding a fuse to it? Edited April 4, 2012 by pegasus bridge Quote Link to comment Share on other sites More sharing options...
Blobby Posted April 4, 2012 Report Share Posted April 4, 2012 (edited) I've been using one of these for a couple of years now, works very well as long as you dont connect it up the wrong way round (you only get one shot and its blown) and you dont use any battery above 8amp, if you connect to a 17amp battery, you get a lots of smoke and smell only cost £4.95 with free p&p on fleebay Edited April 4, 2012 by Blobby Quote Link to comment Share on other sites More sharing options...
pegasus bridge Posted April 4, 2012 Author Report Share Posted April 4, 2012 I've been using one of these for a couple of years now, works very well as long as you dont connect it up the wrong way round (you only get one shot and its blown) and you dont use any battery above 8amp, if you connect to a 17amp battery, you get a lots of smoke and smell thats interesting - i just thought as the voltage was the same it wouldnt have made any difference to it i wonder if a fast blow fuse would protect it from this ? did you add the diode bit to yours? Quote Link to comment Share on other sites More sharing options...
HW682 Posted April 4, 2012 Report Share Posted April 4, 2012 thats interesting - i just thought as the voltage was the same it wouldnt have made any difference to it You are correct, as long as it is 12V the capacity of the battery (eg 7amphour or 17amphour) shouldn't make any difference. This is a lot of confusion over this. Will sort out the diode etc later. A bit knackered after a 5 hour slog back over the pennines due to the snow this evening. Quote Link to comment Share on other sites More sharing options...
HDAV Posted April 4, 2012 Report Share Posted April 4, 2012 Love the instructions "infinitely" and then "256 steps" :lol: What is a Single Led "COLGLE" Dimmer anyway? :hmm: I would be somewhat concerned using this........ Quote Link to comment Share on other sites More sharing options...
pegasus bridge Posted April 4, 2012 Author Report Share Posted April 4, 2012 Love the instructions "infinitely" and then "256 steps" :lol: What is a Single Led "COLGLE" Dimmer anyway? :hmm: I would be somewhat concerned using this........ its 'chinglish' Quote Link to comment Share on other sites More sharing options...
steve_b_wales Posted April 4, 2012 Report Share Posted April 4, 2012 I tried a very similar device on my new rota, but there was a 'whining' sound coming from the motor, as it is on yours.There is no noise when connected directly to the battery Would this harm the motor in any way? Quote Link to comment Share on other sites More sharing options...
Kes Posted April 4, 2012 Report Share Posted April 4, 2012 I tried a very similar device on my new rota, but there was a 'whining' sound coming from the motor, as it is on yours.There is no noise when connected directly to the battery Would this harm the motor in any way? I've had this whining with my rotor and the original speed control device. It does not whine when connected directly to the battery - is this because there is some residual resistance in the speed controller ? I've taken it to bits and greased it, so its not 'tight' (even if its owner is !) Quote Link to comment Share on other sites More sharing options...
Blobby Posted April 4, 2012 Report Share Posted April 4, 2012 thats interesting - i just thought as the voltage was the same it wouldnt have made any difference to it i wonder if a fast blow fuse would protect it from this ? did you add the diode bit to yours? I didnt add anything else as Im not sure what a diode is, all I know is that when I use a 7amp battery its fine, but when I use a 17amp battery it works for a few minutes then goes up in smoke, (a little embarising when showing off to all your mates) I also bought an on/off 12v remote for my flapper, also £4.95 and that works really well. I would like the info and on the diode, what it is and where to fit it. Quote Link to comment Share on other sites More sharing options...
pegasus bridge Posted April 4, 2012 Author Report Share Posted April 4, 2012 I didnt add anything else as Im not sure what a diode is, all I know is that when I use a 7amp battery its fine, but when I use a 17amp battery it works for a few minutes then goes up in smoke, (a little embarising when showing off to all your mates) I also bought an on/off 12v remote for my flapper, also £4.95 and that works really well. I would like the info and on the diode, what it is and where to fit it. I have one of those on its way, going to use it just for the flapper. I will keep this thread updated! Quote Link to comment Share on other sites More sharing options...
Catweazle Posted April 4, 2012 Report Share Posted April 4, 2012 I don't know the controller design, so this is just a guess, but I reckon the controller is actually working by switching the power to the motor on and off very quickly, rather than actually regulating the voltage to it This is known as a PWM controller. There are several reasons for this method, semiconductors that switch on / off don't have to dissipate as much heat, can be made smaller, cheaper, and require much smaller heatsinks. The high frequency switching is causing the whine some have reported hearing. The switching will cause a lot of back EMF ( the spikes I wrote about earlier ), whether the device survives this or not is down to the spec of the output stage of the design. A diode, connected across the motor connections, would kill the back EMF before it could damage the controller. However, diodes have a nasty habit of failing in a way that leaves them short circuited, which could blow the controller anyway, so you need to be pretty sure of the spec before adding one. Here is a link to a circuit that uses a 1N4004 diode to kill back EMF, your controller might already have this, or might not. The designer notes that the diode might need uprating for some motors. http://www.solorb.com/elect/solarcirc/pwm1/ Quote Link to comment Share on other sites More sharing options...
Trooper82 Posted April 8, 2012 Report Share Posted April 8, 2012 Found one which looks the same on that place for £7.50 in Bristol, for that price I,ll give it a go. thanks for tip. Jim Quote Link to comment Share on other sites More sharing options...
pegasus bridge Posted April 8, 2012 Author Report Share Posted April 8, 2012 after some sound advice i've got some components on the way to address the 'spiking' issue, and to set up a safety system to prevent accidental damage through connecting the battery the wrong way round, it should hopefully result in a durable remote& speed controller! - once its finished i will put the specs up here.. Quote Link to comment Share on other sites More sharing options...
la bala Posted April 9, 2012 Report Share Posted April 9, 2012 well thats really done my head in. :blink: Quote Link to comment Share on other sites More sharing options...
pegasus bridge Posted April 9, 2012 Author Report Share Posted April 9, 2012 well thats really done my head in. :blink: What has? Quote Link to comment Share on other sites More sharing options...
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