ok, here's the deal:
power in our shop/garage is non-existent and we are running all the low-power stuff off of the (old and shitty) house electrical circuit (extension cords).
For the higher power equipment (planer, heat blankets, etc) we just purchased a generator so we don't trip the house. My question is:
the generator's manual mentions protecting solid-state devices with some sort of regulator as the signal coming out of the generator is quite dirty. I am using an SSR to control the blankets. Should I be worried about adding capacitance / other to clean it up? Or does it not really apply to our case as control of the blanket doesn't need to be hyper accurate?
Looking forward to the electrical advice!!
SSR protection with generator?
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Hi Billl,
A capacitor won't do much, if anything, for regulating (or even smoothing) fluctuating AC voltage. If you tried to use a capacitor with AC, you'd basically just end up with a 90 degree voltage/current phase shift. Your PID controller probably won't like that any more than it will like fluctuating voltage. What you really need is an AC voltage regulator of some sort. One of the handiest (and cheapest) devices around for that job is a UPS unit like the one you probably use to protect your computer from power surges. You can just run your PID off the UPS, and run your heat blanket (high voltage/current side of the SSR) off the 'dirty' generator power. A bigger UPS would even run your heater, but the heater circuit doesn't really need that much regulation.
Your SSR's 'solid state' side is powered by an output signal from your PID, so the solid state part of the relay is pretty well protected via the PID. The solid state side of the relay basically acts as a switch for the more substantial 'other side' of the relay. The side of the relay that's connected to your heat blanket is pretty tolerable of wide voltage variations. Your heat blanket can handle the voltage variations as well. But your PID controller is most likely not so easy going, so you probably want it's voltage supply to be pretty stable. The PID pulls very little current, so you might even be able to run it off the house current via an extension cord, then run the heater side of the relay off of the generator power.
Hope that all makes sense. I get a little blurry brained this time of the day/night.
G-man
A capacitor won't do much, if anything, for regulating (or even smoothing) fluctuating AC voltage. If you tried to use a capacitor with AC, you'd basically just end up with a 90 degree voltage/current phase shift. Your PID controller probably won't like that any more than it will like fluctuating voltage. What you really need is an AC voltage regulator of some sort. One of the handiest (and cheapest) devices around for that job is a UPS unit like the one you probably use to protect your computer from power surges. You can just run your PID off the UPS, and run your heat blanket (high voltage/current side of the SSR) off the 'dirty' generator power. A bigger UPS would even run your heater, but the heater circuit doesn't really need that much regulation.
Your SSR's 'solid state' side is powered by an output signal from your PID, so the solid state part of the relay is pretty well protected via the PID. The solid state side of the relay basically acts as a switch for the more substantial 'other side' of the relay. The side of the relay that's connected to your heat blanket is pretty tolerable of wide voltage variations. Your heat blanket can handle the voltage variations as well. But your PID controller is most likely not so easy going, so you probably want it's voltage supply to be pretty stable. The PID pulls very little current, so you might even be able to run it off the house current via an extension cord, then run the heater side of the relay off of the generator power.
Hope that all makes sense. I get a little blurry brained this time of the day/night.
G-man
thanks g-man
Thanks a lot for your reply G-man. As always detailed and informative. We'll run the PID off the house circuit and won't need to worry about cleaning up the voltage to the blankets.
Pressing the first pair this weekend if all stays on track... Can't wait!!!
Pressing the first pair this weekend if all stays on track... Can't wait!!!