Filippo Morelli wrote:
Glad you chimed in, Fred. I appreciate it. My heating blanket for bending actually has a built in thermistor. That should work for bending?
On the timer, you're telling me to go lower tech and save money? How nice of you!
Filippo
On the timer, you're telling me to go lower tech and save money? How nice of you!
Filippo
That PID does take these thermistor inputs: "Input: Thermo Resistor: PT100, Cu50". But the temp the thermistor senses will be inside the blanket -- generally higher than the temp at the wood surface. So I'd go with a TC like Fred says. I like the wire type TCs, as the larger sheath pushes the blanket away locally. E.g., http://www.ebay.com/itm/310382864123
Also agreed on the wall timer. I've been using one like this: http://www.homedepot.com/p/100685852
as it has a 3 position switch and doesn't require 'turn past' like the springed ones.
One odd thing on that PID and SSR combo: The PID spec says, "Main Output: SSR: Open circuit: 4V, Closed Circuit: 24V 40mA DC". I.e., it outputs 4V for off and 24V DC for on.
While the SSR says, "Input Voltage:DC 3-32V", so it should be on at 4V and at 24V DC.
But they've sold a bunch of these, so probably the PID doesn't push enough mA at 4V to switch the SSR.
I generally like SSRs except for 2 things: the 'click' of a regular relay is often helpful to know what it's doing, and when an SSR fails (rarely), it normally goes closed circuit. I like to wire a light in parallel to the load to monitor what the SSR is doing.
