Switch module replacement help

Thread Starter


Joined Apr 18, 2010
Hopefully the Moderators will allow this post. I am asking for assistance in locating a replacement for the module, not for assistance in modifying the components within the module.

I don't know where to start to find a replacement for the module pictured.

Basically I bought a pillar drill 9 years ago because it was on special offer, and I /knew/ for what I wanted to follow for hobbies it would come in useful. Unfortunately I haven't been able to get together enough space to put it up until now (seems like I have managed to bodge around the problem for too long).

So I plugged it in, turned it on, left it going for the 15 minute run in period the instructions suggest, then drilled my first hole. No probs. Drilled the second hole no problems either.
Came to the third hole, and the power button wouldn't latch on.
Took it apart (warranty ran out 8 years ago, woops), and in the switch module, one of the wires looked corroded. It was meant to be a multistrand wire, but the strands going into one of the solder pads had just become a green lump instead. The other end of that wire wasn't looking too good either (this was just placed against a coil of copper threads). This wire was used to attach to what I believe is a magnetic induction coil, which was used to hole the on button into place.

So what I am looking for, is a complete switch replacement module. The current one has 4 crimp terminals (2 in 2 out for isolation of the 240VAC). This module is after the live wire fuse.

These modules must be common for use within machinery, so does anyone know a good place (in the UK?) where I can obtain one?
Dimensions roughly 40x35x25 mm.

This module is situated within a plastic enclosure within the drill press. Hopefully someone can assist with locating a supplier, as the alternatives I can think of are blanking the original switch area, and installing an external one (I guess if done properly [panic switch on bench type of thing], wouldn't be so bad, but I would rather not, and I am not asking for ideas on that in here)

The module is marked, KJD6 5E4 T85, putting the first two into google comes up with lots of information on the manufacturer of the module, and distributors talking about how to buy 1000s for your next new invention, but I only want the 1.


Last edited:


Joined Mar 24, 2008
This seems like a legitimate request, but I suspect a moderator will be along and move into the Electronics Projects thread soon.

This is part of the drill? What is the make and model.

When my old Makita bit the dust (it was dropped onto a concrete floor around 8 feet while working on a Robotic Combat arena by a friend) I went to eBay and bought a known defunct model (same drill) for a song.

Thread Starter


Joined Apr 18, 2010
I kept it out of the projects, as I didn't think it really qualified as a project.
It is a Power Craft PDB 16/500. The name doesn't really help a lot on searching. Power and Craft appear to be quite popular terms for some reason.

This is a pillar drill (sits on a bench), and basically this is the main ON/OFF switch which transfers the (only) power into a 'large' AC motor.

Purchasing another drill for parts I suppose is a possibility. I guess in most cases it is the motor which goes.
This actually appears to be a similar drill, same size, same shape..... http://cgi.ebay.co.uk/CLARKE-5-SPEE...Home_Garden_PowerTools_SM&hash=item2a082c4cd0

Major difference though, on the last photo there is a silver plate. On my drill that silver plate with the wires going in and out is where the switch should be! Hmm, wonder if it is a fault common to these types of drills. (other major difference, because I only tool the grease paper off today, mine ain't rusty!)


Joined Feb 28, 2009
It looks like the module contains a relay! That would move it into the realm of a self contained Start/Stop station. The relay provides a significant safety feature. On power loss, the unit will not self actuate upon power return. OP needs an external box to duplicate the function if he can't find a domestic supplier of the OEM unit..

Thread Starter


Joined Apr 18, 2010
Yes, the box is effectively a self-latching dual pole relay. The coil power is what was through this tiny wire, and the off button, as well as physically moving the 'switch' 'rod' was also a push to break on the coil wire.
The automation direct switches do not replicate this. I wonder if I would get more luck searching for a relay then?
(or I could just use the wife to hold the button in I suppose. Would be a bit like a dead-man switch, when she faints from the sight of blood :) ).


Joined Apr 26, 2005
If your wife holding the On switch down allows the relay to be energized, the only problem area is the latching contacts. That is two wires and the connections.

From what I see, your relay contacts could use burnishing ... or replace the relay.

Take those two phillips head screws off and remove the cover. Take another picture and get the number off the relay.


Joined Dec 5, 2009
The trick is.. to get the drill up to speed while holding the button, then drill the hole as fast as possible when you let go, before the drill spins down. ;)

No, dont do that. This should be no problem to swap the relay, or even replace the bad wire.

Thread Starter


Joined Apr 18, 2010
The issue with it is, that this whole unit is the relay effectively.
I would have to replace the coil as the minumum I think. For interest only, the markings are AC250V GWE

I would rather not mess around and would rather replace the whole unit if I can. I think that there is another make, silverline, which looks to be an exact copy of the drill, so I am going to try and call them tomorrow to see if they could do a spare (ok, my drill is possibly a copy of them).

Attached is a simple schematic, this is of the whole pillar drill. Perhaps I wasn't clear earlier when I said it was basically a relay, it isn't a switch that energises a relay running the motor, the switch is the relay that energises the motor (in that with a relay, you use a coil to hold a switch in place, this switch energises the coil which holds itself in place).

The red box is the area covered by this device. I haven't put in ground, as this is suitably attached to all metal objects, and doesn't come into the red box (being plastic enclosure).

The green bar, is a metal bar, with a plastic coating, and on one side is a metal plate (k8.2), the other is an identical metal plate (directly underneath in the diagram).
The on button, pushes the bar down onto the coil. This act closes the circuit K8.2 and it's pair.
A parallel circuit to the motor, goes off and around the coil, supposedly energising it. This in theory keeps the metal bar held down, and the switch energised. On the diagram, you can see that the coil circuit goes through the off button, and a push to break switch.

When the off button is pushed, the first action is the push to break, which causes the coil to de-energise. If the bar does not move away from the switches, the action of the off button actually moves the bar away from the switches physically. The push to break switch is in fact just another metal bar, sprung against two contacts.

Although these contacts don't look nice and shiny and new, I am not sure that there would be so much there that it would stop the coil being energised (but that is based on no experience in quantative AC analysis, to me AC either works, or has a large pot hole where the component used to be).

Thanks for the inputs chaps.