For Sale: 3 new Watlow Digital PID temp controllers

[Jim Ball]

-SOLD-

Small 1/32 DIN size perfect for controlling the surface heater in a Fox-style side bender.
I got these as sales samples several years ago when I was designing industrial ovens for a living. The model has been discontinued, but these are brand new & have been sitting in the original boxes on a shelf in my shop gathering dust. I have four, but I intend to use one for my own side bender if I decide to upgrade to an electric surface heater.
The 935B's are identical to the 935A series except the series 935B option provides a separate input to initiate timer start from a remote switch.

You can download a .pdf manual here: https://www.watlow.com/downloads/en/manuals/935ae_l.pdf



$50.00 each & I'll pay the shipping (USA only)
email me at jimball 'at' cpol 'dot' net

[Jim Ball]

FYI: Watlow is a top shelf supplier of industrial controls. These controllers sold to OEM's for around $150.00-$200.00 new and are rugged, professional quality controllers. These are NOT your cheap $30 Chinese "will it work" junk controllers.

[Kevin in California]

Okay Jim I am not much of an electronics guy. So you can put these one of these in the circuit to the light bulbs, along with a thermocouple, and you can set and regulate the temperature? They also have a count down feature?

[Jim Ball]

Okay Jim I am not much of an electronics guy. So you can put these one of these in the circuit to the light bulbs, along with a thermocouple, and you can set and regulate the temperature? They also have a count down feature?

There needs to be a relay in the circuit. Controllers of this type are not intended to act as direct power switches. Solid State Relays can be purchased for under $10.00 Also, you would have better luck using the controller with an "electric blanket" surface heater. I'm building my side bender with bulbs and a mechanical timer switch for now. I'll upgrade to the Watlow controller & a surface heater at a later date.
See this thread about surface heaters: http://www.acousticguitarconstructionfo ... p?f=8&t=45

[Daniel P]

I'm using this SSR with a Fuji controller. You can use mechanical relays, but they work best with higher thermal mass than bending setups. Glass kilns, for example, have much fewer on-off cycles to maintain target temperature as they hold heat in the glass and crucible. Side bending setups have lower thermal mass, and often have more frequent on-off cycles - solid state relays are better suited for the increased number of cycles.

These Watlow controllers should work great with a SSR.

[John Link]

Jim,

What might be helpful would be for you to describe a list of recommended parts along with a description of how to hook them up to the point of attaching the heating blanket - something along the lines of what it would take to build a turnkey unit, such as can be purchased from the luthier supply houses.

I already have one from LMI and can testify it works perfectly and is a much better way to go than sticking in a meat thermometer and watching a timer, so I am not in the market to buy anything. I just think this might be helpful to those without your knowledge of how to set these things up, and help everyone in the process.

[Daniel P]

Here is a pretty good outline of one way to build a digital temperature controller:

http://fretsnet.ning.com/forum/topics/d ... t%3A118289