DaveL
Old Oak
That would still need a capacitor to smooth the rectified AC output and it must not be just a trickle charger, they would not supply enough current.Mike G":220ukk3f said:
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Running a cordless drill from an AC transformer
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Mike G
Petrified Pine
Hmmm.....
Why is this so difficult? There must be a bit of kit which takes 240V DC in and outputs 15 to 18V DC out without me having to get "Electronics for Dummies" and a new soldering iron.
Why is this so difficult? There must be a bit of kit which takes 240V DC in and outputs 15 to 18V DC out without me having to get "Electronics for Dummies" and a new soldering iron.
DaveL
Old Oak
Well you could get one of these, but you need to know how much current the drill needs.
https://www.ebay.co.uk/itm/264759172436
https://www.ebay.co.uk/itm/264759172436
Mike G":14z59inp said:
Which is almost what I said the other day. You need the battery still fitted as well as the charger to drill wiring. The battery does the hard work when required and the charger just tops it up.
Mike
This is probably miles too late but....
Yes you can but as others have said you need a rectifier and a big smoothing cap. The sizing of all of this depends on your load which determines how much electrical power you need.
A safer an easier way is to buy a nice safe enclosed switched mode power supply such as one of these, but again you need to select one with enough power:-
https://uk.farnell.com/w/c/power-line-p ... rt=P_PRICE
Although you could, I’d not use the drill own switch or mechanical direction control just use a double pole changeover relay and wire direct to the motor in the drill. I’d use a micro switch to control the direction relay.
Hope that helps.
This is probably miles too late but....
Yes you can but as others have said you need a rectifier and a big smoothing cap. The sizing of all of this depends on your load which determines how much electrical power you need.
A safer an easier way is to buy a nice safe enclosed switched mode power supply such as one of these, but again you need to select one with enough power:-
https://uk.farnell.com/w/c/power-line-p ... rt=P_PRICE
Although you could, I’d not use the drill own switch or mechanical direction control just use a double pole changeover relay and wire direct to the motor in the drill. I’d use a micro switch to control the direction relay.
Hope that helps.
Buy the kit Mike, or youll burn your house down.
https://www.hiddentvlift.co.uk/our-prod ... pathway-13
I bet youll spend that on the home made pieces.
https://www.hiddentvlift.co.uk/our-prod ... pathway-13
I bet youll spend that on the home made pieces.
Mike G
Petrified Pine
stevegruk":25ulol9f said:
Hi Steve, and welcome.
As it happens, that is precisely what I've got. Everything self contained within a box, so pretty foolproof. I reckon I'll be starting work on the electrics this coming weekend, so we'll see what we see.
Sheffield Tony
Nordic Pine
sunnybob":24hcmr7r said:
That looks awfully like a windscreen wiper motor.
Having designed control electronics for a few motors, I have been caught out more than once by underestimating the stall current. For the wiper motors 15A might be seen. I wouldn't be surprised if it is more for a drill motor. The PSU will see that briefly on starting. The other common oversight is where the energy goes when braking / stopping. Most controllers direct it back to the battery to get rid of it. Mains PSUs don't always like that.
Not sure I've been all that much help here - sorry.
Back in '89, I was the secretary of a target shooting club. I bought 5 turning target units that were using windscreen wiper motors They had huge torque, snapping a man sized target frame through 90 degrees almost as fast as you could see. They ran off full sized car batteries that in the end I rigged up to be on permanent trickle charge because the targets drained the batteries so quickly.
Its all about the torque, so DO NOT under estimate 12 volt dc power requirements. :shock:
Its all about the torque, so DO NOT under estimate 12 volt dc power requirements. :shock:
Back in '89, I was the secretary of a target shooting club. I bought 5 turning target units that were using windscreen wiper motors They had huge torque, snapping a man sized target frame through 90 degrees almost as fast as you could see. They ran off full sized car batteries that in the end I rigged up to be on permanent trickle charge because the targets drained the batteries so quickly.
Its all about the torque, so DO NOT under estimate 12 volt dc power requirements. :shock:
Its all about the torque, so DO NOT under estimate 12 volt dc power requirements. :shock:
Mike G
Petrified Pine
sunnybob":1e01o9un said:
Don't forget that I have the drill's gearbox at my disposal, and the torque control. If there is too much torque required the torque control will ratchet. If it is too much of a strain in the faster gear, I'll use the slower one.
I think your biggest problem will be the continued torque.
When a drill first starts up there is high load for a fraction of a second, then it basically runs at a fast idle while its being used.
Operating a screw drive mechanism attached to a considerable weight and friction of moving parts is putting continuous high load. And dont forget on the way down the weight will be trying to make the motor go faster.
I applaud your efforts, and I'm no stranger to sticky back plastic and toilet roll construction, but I am concerned you are putting all this stuff out of sight and in a flammable cabinet.
Stay safe.
When a drill first starts up there is high load for a fraction of a second, then it basically runs at a fast idle while its being used.
Operating a screw drive mechanism attached to a considerable weight and friction of moving parts is putting continuous high load. And dont forget on the way down the weight will be trying to make the motor go faster.
I applaud your efforts, and I'm no stranger to sticky back plastic and toilet roll construction, but I am concerned you are putting all this stuff out of sight and in a flammable cabinet.
Stay safe.
AJB Temple
Sequoia
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Is this set up not basically the same as an electric window lift mechanism in a car?
The switch action is different...at least on my car...might be the same on a TeslaAJB Temple":3o93nh9h said:
Mike wants to press the same pushbutton switch to go up (if the TV is down) or down (if the TV is up). In my car I have a toggle switch.
AJB Temple
Sequoia
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Even Tesla has a toggle switch. Musk did not specify voice control for the windows. But I think all cars have a single press for all the way up (or down) and either hold or press again to stop part way.
Really I feel this needs a remote control solution :lol:
We also need to remember that Mike has a sore finger and may need to factor that into his design.
Really I feel this needs a remote control solution :lol:
We also need to remember that Mike has a sore finger and may need to factor that into his design.
this is a very interesting thread. Curious to see the end result.
Just a thought Mike: what if the Tudor rose pivoted on a horizontal axis, so that you push the top half to go up, and the bottom half to go down? it would mean a slight taper, or bigger gap around the rose...
It is not as neat as the solution you envisage however.
Just a thought Mike: what if the Tudor rose pivoted on a horizontal axis, so that you push the top half to go up, and the bottom half to go down? it would mean a slight taper, or bigger gap around the rose...
It is not as neat as the solution you envisage however.
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A proximity sensor would have been ideal. Just touch an area but no need for it to move but being active, it would need power (very low) to be applied all the time.
Bob
Bob
Sheffield Tony
Nordic Pine
AJB Temple":1p5ue3ne said:
Need an IR receiver to detect the TV remote power on signal, and raise the TV automatically for you. Perhaps a strategically placed IR transmitter too to relay the power on signal to the TV inside the cupboard so that it can be "warming up" as it rises.
Isn't it ironic that as a kid, we had valve TVs that you had to turn on ahead of time; they had to warm up. Then for a while we had the luxury of TVs that came on almost instantly. Now we are back to turning them on ahead of time; they need to boot up.
And back we go to complex solutions. 
the battery will run on 12v just fine (or should if the confuser doesn't have a low voltage shutoff)
so a 12v 4amp regulated power supply would be ideal.
this should do it
https://uk.rs-online.com/web/p/embedded ... s/1065830/
you are going to have take the drill apart and look at how the forward/reverse works. some move the contact on the switch others move a separate switch. either will be fine but as you are going to be bypassing it all you'll need to look at how.
next you'll want to wire your toggle switch to account for how it reverses directions, that could be tricky if it's a separate switch, bit easier if it's shifting contacts in the trigger.
I'm afraid you will be doing a bit of wiring and soldering to bypass it all, do not bypass the brain box, it's doing all the PWM for the motor speed control.
good luck, I hold no responsibility for when it goes wrong.
the battery will run on 12v just fine (or should if the confuser doesn't have a low voltage shutoff)
so a 12v 4amp regulated power supply would be ideal.
this should do it
https://uk.rs-online.com/web/p/embedded ... s/1065830/
you are going to have take the drill apart and look at how the forward/reverse works. some move the contact on the switch others move a separate switch. either will be fine but as you are going to be bypassing it all you'll need to look at how.
next you'll want to wire your toggle switch to account for how it reverses directions, that could be tricky if it's a separate switch, bit easier if it's shifting contacts in the trigger.
I'm afraid you will be doing a bit of wiring and soldering to bypass it all, do not bypass the brain box, it's doing all the PWM for the motor speed control.
good luck, I hold no responsibility for when it goes wrong.
Mike G":26vodkp0 said:
I didn't see anywhere that recommended a power supply, although I could have missed it.
was trying to be helpful instead of stepping on peoples toes, honest guv. might want to check the speed of the drill at full chat, could be a bit sharpish on the up. (yes even on low speed)
thinking first tele to be launched to space without a rocket.
Mike G
Petrified Pine
ALL posts are helpful here (and gratefully received), in that this is an area of weakness in my DIY armoury. Anyway, this is the basic kit of parts I'm working with:
Plus of course wire, solder, and so on. My soldering is somewhere closer to adequate than competent, but good enough. I hope.
I'm planning on making a start on this over the weekend, and the first thing I'm going to do is wire power to the drill and pull the trigger.
Plus of course wire, solder, and so on. My soldering is somewhere closer to adequate than competent, but good enough. I hope.
I'm planning on making a start on this over the weekend, and the first thing I'm going to do is wire power to the drill and pull the trigger.
Electronics is also a mystery to me.
My soldering improved when I bought some proper flux, just in case you don't already have some. it's very helpful.
https://www.amazon.co.uk/flux-soldering ... 01N6B6E9W/
My soldering improved when I bought some proper flux, just in case you don't already have some. it's very helpful.
https://www.amazon.co.uk/flux-soldering ... 01N6B6E9W/
Lons
Old Oak
In my case the improvement was after buying a soldering station so I can control the temperature, Makes it much easier, plus the correct flux and solder.sammy.se":2nl51o2y said:
Mike G
Petrified Pine
Some actual progress to report, and a question or two.
I took the drill apart:
That's power in from the battery at the bottom right, and next to it is some odd bit of aluminium......back to that in a minute. Furthest left is the battery read-out thingy. These all connect to the switch unit, and thence just 2 wires to the motor.
On the top of the switch unit is the reverse switch. This is crucial to my plans, and it's not very convenient:
The first job was to ascertain that everything worked, so I rigged up the motor to the power unit, and pulled the trigger:
It all worked beautifully. The output of the AC to DC transformer only registered 2 out of three lights on the battery strength meter thing:
That's with the little dial controlling output on the transformer cranked up to maximum. But the speed of the motor looked fine to me, and it has plenty of torque (I couldn't stop it with my bare hands).
I pulled the main switch permanently on, then rigged up the pair of 2 way micro-switches and ran it again, and that all worked perfectly. Every change to one switch or the other changes the state of the circuit:
In principle then, the electrics of this lift thing are going to work.
OK, so my questions. What is this thing? Is it some sort of heat sink? If so, why?
And secondly, the reversing switch. The drill one has a tiny little plastic lug/ pin on the top and a relatively stiff mechanism. This isn't going to last 5 minutes in any mechanism I am planning to make. So, I want a 12v double pole switch with no neutral position (ie on/ on reverse). Can anyone tell me precisely what these things are called?
I took the drill apart:
That's power in from the battery at the bottom right, and next to it is some odd bit of aluminium......back to that in a minute. Furthest left is the battery read-out thingy. These all connect to the switch unit, and thence just 2 wires to the motor.
On the top of the switch unit is the reverse switch. This is crucial to my plans, and it's not very convenient:
The first job was to ascertain that everything worked, so I rigged up the motor to the power unit, and pulled the trigger:
It all worked beautifully. The output of the AC to DC transformer only registered 2 out of three lights on the battery strength meter thing:
That's with the little dial controlling output on the transformer cranked up to maximum. But the speed of the motor looked fine to me, and it has plenty of torque (I couldn't stop it with my bare hands).
I pulled the main switch permanently on, then rigged up the pair of 2 way micro-switches and ran it again, and that all worked perfectly. Every change to one switch or the other changes the state of the circuit:
In principle then, the electrics of this lift thing are going to work.
OK, so my questions. What is this thing? Is it some sort of heat sink? If so, why?
And secondly, the reversing switch. The drill one has a tiny little plastic lug/ pin on the top and a relatively stiff mechanism. This isn't going to last 5 minutes in any mechanism I am planning to make. So, I want a 12v double pole switch with no neutral position (ie on/ on reverse). Can anyone tell me precisely what these things are called?
Your mystery gadget is probably the variable speed controller and yes the electronics is mounted on a heat sink. And I think you are looking for a DPDT switch - double pole double throw. should say if it has an off position or not. may also say 'changeover' switch as there is no off.
Mike G
Petrified Pine
Thanks Robert. As I don't need variable speed control, can I just cut this away, and wire between the two terminal it comes from?
I've found a switch which looks as though it would do the job:
https://www.amazon.co.uk/Pxyelec-Mo...reverse+polarity+switch&qid=1607876809&sr=8-3
Anyone know something better, or any good reason why that one wouldn't work?
I've found a switch which looks as though it would do the job:
https://www.amazon.co.uk/Pxyelec-Mo...reverse+polarity+switch&qid=1607876809&sr=8-3
Anyone know something better, or any good reason why that one wouldn't work?
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The item on the heatsink is quite likely a MOSFET - a sort of transistor and both it and the cooling of it are VITAL so dont be tempted to discard or damage it.
The switch you want is a two pole changeover switch but it MUST be capable of high current when switching DC. IGNORE any AC current ratings
Look for ones designed for automotive use for better chance of being man enough for the job.
There is a risk that switching the motor direction without removing the power will blow up the controller. This is why drill switch mechanisms are interlocked to only allow direction reversal when the power is off.
This could muck up your entire project in a trice.
HTH
Bob
The switch you want is a two pole changeover switch but it MUST be capable of high current when switching DC. IGNORE any AC current ratings
Look for ones designed for automotive use for better chance of being man enough for the job.
There is a risk that switching the motor direction without removing the power will blow up the controller. This is why drill switch mechanisms are interlocked to only allow direction reversal when the power is off.
This could muck up your entire project in a trice.
HTH
Bob
I O II implies a centre off position. You also need to consider switch design as in what the lever looks like and how far it has to move.
And I'd try bypassing the entire drill switch wiring rather than go cutting wires. Full speed will still go via the speed control.
And I'd try bypassing the entire drill switch wiring rather than go cutting wires. Full speed will still go via the speed control.
Mike G
Petrified Pine
9fingers":1q8lg2xp said:
I know, Bob. The mechanical over-centre rocker thing that will sit on the shelf edge will trigger the off switch before it triggers the change direction switch. Its exact design will depend on the switches I am working with, but the principle is pretty simple. I guess if it would help if I drew it.
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Mike G":295pqrw8 said:
OK if your design ensures that the motor has stopped before the direction switch is moved then you should be fine.
I'm torn between suggesting that the controller is abandoned completely and your power on/off switch controls the mains into the power unit or that you continue as you are.
You hopefully can see parallels when we ask building type questions and you feel a certain "I would not have started from there" feeling :lol:
Bob
Pete Maddex
Old Oak
Drop the speed controller and go with my diagram, I don't think that it will be easy to link the drill reverse to the TV lift.
Pete
Pete
Mike G
Petrified Pine
I'll go back and have another look at that, Pete. And yes, Roger, I take your point.
In the meantime, here is the switch mechanism for the Tudor rose. The first one is the starting position, and the second has the rose 15mm (ish) in whilst the TV is up:
The little screw head adjacent to the micro switch is obviously adjustable to give minute control over exactly when the switch triggers. All of the contact surfaces are plastic, and obviously the thing in the middle is a push-to-open cabinet door catch.
In the meantime, here is the switch mechanism for the Tudor rose. The first one is the starting position, and the second has the rose 15mm (ish) in whilst the TV is up:
The little screw head adjacent to the micro switch is obviously adjustable to give minute control over exactly when the switch triggers. All of the contact surfaces are plastic, and obviously the thing in the middle is a push-to-open cabinet door catch.
Mike G
Petrified Pine
9fingers":2ixqq1rr said:
Could you just expand on this a bit Bob. At the moment I have a positive and negative going into and out of the switch unit, which is taped fully on, and which serves no control function for my set up. I'm really not sure what it brings to the party.
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Mike G":2c0jgbv3 said:
Indeed the controller (the one item you started with that is designed to handle the motor switching current) is not being used.
Therefore connecting the motor to the power supply via the reversing switch is all you need.
Your on/off switch can be connected between mains in and the power supply where the current is very much lower and AC - more suited to commonly available switches. Similarly the limit switches can be on the mains side of the design.
Does this help you?
Bob
Mike G
Petrified Pine
It's got me completely puzzled, I'm afraid. Are you suggesting that my 2 way switching should be at 240V? If so, I'd rather go out and buy a commercial lifter as don't have the skills necessary to safely go playing around with 240V. DaveL has supplied the 2 way microswitches, so I suspect they are properly rated for the job in hand. Therefore I'm not sure what problem I would be avoiding by doing the on-off switching on the mains side of the transformer.