I want to build a Capacitive Discharge Unit to drive my Peco twin coil switch machines. I don’t seem to be able to throw my Peco turnouts with a simple momentary contact button and A/C power alone.
Can anyone point toward any kit CDU’s or parts list and diagram that will allow me to build one for a cost savings over the already made ones. I’m on a budget.
Thanks
Take a look here. Sould help you out.
Scroll down to the heading “Current Blocking Switch Machine Power Supply”. The top one in the white block in that section is what you want. Fast recharge, simple circuit. I built essentially the same thing from the Kalmbach book “Practical Electronic Circuits for Model Railroaders” by Peter Thorne many many years ago. The second circuit in that block just adds an LED that lights when the cap is charged - not necessary, but for a $1 more in parts maybe it would be a fun addition, more blinky lights impresses some people.
–Randy
Circuitron sells the Snapper that operates off of AC as well as DC.
I built the below some years ago to fire a Peco three way.
http://www.awrr.com/cdsupply.html
Rich
Lots of good suggestions and resources. BTW, I seem to remember someone posting a link to a vendor who offered kits as well, for a fairly modest price?
I just did a Google search for capacitive discharge unit kit
One result below.
http://www.talkingelectronics.com/projects/CDU-2/CDU-2.html
Rich
Do a Google search and then click on Images, you will get loads of circuits.
Rich
Of theirs, I’d go with the MkIIB - the top one only has 2000uF total, which is on the low side, the MkIIB has 4400uF for significantly more storage - mainly important if you have situations like crossovers where more than one switch motor fires at the same time.
–Randy
The one i did to fire the peco three way, I increased c2 to 10,000 ufd.
Rich
Rich/Randy, thanks. Today all my brain power went to trouble shooting some IT issues so I needed to be fed with a spoon! The kit looks good!