I have converted the stand for my Pace TD-100 to use the instant setback feature.
Thanks to TPI who checked how the official Pace ISB cubby works.
When _SW is connected to GND on the ISB connector, the station drops the temperature to 350° F after 45 seconds.
My first idea was to use a long-lever microswitch (V-153-1C25 type from eBay) mounted from the inside (see picture). This type has the ideal length for the barrel the iron goes into, but unfortunately it also has rather high activation force and travel, so finding a suitable position and angle for it turned out to impractical.
Instead I used a small SMD microswitch attached with epoxy to the front of the barrel where it has much lower risk of being fouled by the iron tip.
The type I used -
http://katalog.we-online.de/em/datasheet/434123050816.pdf - is specified for an activation force of 160g +/- 50g. The handpiece with cable and tip only weighs about 80g and it only triggers the switch by gravity alone if the cable is lying on the table, but in practice the small amount of acceleration added when placing the iron in the stand makes it work reliably. When triggered, the weight of the handpiece alone is sufficient to keep the switch held down.
Still, I'd suggest getting a microswitch with the lowest possible activation force.
I used enameled wire routed out of reach of the iron tip to connect to a terminal block bolted to the side of the upper part of the stand so that part is still removable. The lower part of the stand already has the hole for the ISB cable.
I didn't have the male 3-pin Mini-DIN connector needed to plug into the ISB socket on the soldering station, but I did have a 7-pin one, which has three of its pins in the right locations and so can be hacked to fit :-)
https://en.wikipedia.org/wiki/File:MiniDIN-3_Diagram.svghttps://en.wikipedia.org/wiki/File:Pseudo_miniDIN-7_Diagram.pngI have also included some pictures of the Pace ST-30 station. The main components are:
http://www.nxp.com/products/microcontrollers/8_16_bit_legacy/otp_rom/P87C51RA_IA.htmlhttp://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010518As can be seen in the picture of the transformer, this European version can easily be converted to 115V operation.