Hi,
I am making a filament heater. I got the thermocouple working, but now I need to switch the band heaters on and off.
Basically they are wired straight into AC mains via a plug and a 13 am fuse. I got a relay, but its only 6 amp. It wont be strong enough I fear.
Could somebody please recommend a method for switching these heaters on and off?
Thanks.
Do you know the actual power consumption of the heaters? It is probably less than the fuse rating. It is quite possibly less than your relay rating, which means the relay will work.
Get a bigger relay or switch to a SSR Solid State Relay. The SSR can be switched much more rapidly so it's often more useful for control.
Is your relay a single pole? If multiple poles, then wire in parallel for more current rating.
Paul
MorganS:
Do you know the actual power consumption of the heaters?
Thanks Morgan. It is three 85W 220v band heaters wired in series. I have a relay as follows: is 2-Channel 5V Relay Module for Arduino PIC ARM AVR DSP
It can be able to control various appliances, and other equipments with large current
Easy to be controlled by a lots of Microcontrollers( Such as Arduino , 8051, AVR, PIC, DSP, ARM, ARM, MSP430, PLC,TTL logic)
Just use 5v input signal to control
Equiped with high-current relay, AC250V 10A, AC150V 10A; DC30V 10A , DC28V 10A
Would this be suitable?
Paul_KD7HB:
Is your relay a single pole? If multiple poles, then wire in parallel for more current rating.Paul
Hi Paul,
This is the relay I have.. would it fry the board if I try it? The band heaters are 22v 85W..
is 2-Channel 5V Relay Module for Arduino PIC ARM AVR DSP
It can be able to control various appliances, and other equipments with large current
Easy to be controlled by a lots of Microcontrollers( Such as Arduino , 8051, AVR, PIC, DSP, ARM, ARM, MSP430, PLC,TTL logic)
Just use 5v input signal to control
Equiped with high-current relay, AC250V 10A, AC150V 10A; DC30V 10A , DC28V 10A
Will a PowerSwitch Tail work?
The official page says there is a 220V version that can take 20A. That should be plenty.
MikeDutton:
Hi Paul,This is the relay I have.. would it fry the board if I try it? The band heaters are 22v 85W..
is 2-Channel 5V Relay Module for Arduino PIC ARM AVR DSP
It can be able to control various appliances, and other equipments with large current
Easy to be controlled by a lots of Microcontrollers( Such as Arduino , 8051, AVR, PIC, DSP, ARM, ARM, MSP430, PLC,TTL logic)
Just use 5v input signal to control
Equiped with high-current relay, AC250V 10A, AC150V 10A; DC30V 10A , DC28V 10A
Yes, if you can get the relays to switch at the same time. If you can find a double-pole, double-throw relay it would be much better. All relay contacts have a tiny resistance and this causes heating of the contacts. This is the reason for a 10A rating.
Paul
Could I just use one of these and wire the heaters in parallel of it?
85W at 220V is 0.39A You could put a lot of these in parallel on one 10A relay. Like about 25 of them.
0.39A I got that but was sure the calculator was wrong ;D
This relay from DigiKey is 220V and can take 2A. The coil voltage is 5V.
It is three 85W 220v band heaters wired in series.
This doesn't really make sense. Wiring the heaters in series will result in about 1/9 of the heating output of one heater.
michinyon:
This doesn't really make sense. Wiring the heaters in series will result in about 1/9 of the heating output of one heater.
Quite right.. parallel sorry.