Pumprelay

These simple schematics are well known by most of the watercoolers guys and are meant to power on the waterpump in a watercooled PC together with the power supply. I added a simple visualisation of the power to the pump by means of a led. This led circuit is actually the one on my AC-led page and shows if there's really mains voltage going to the pump (not just if the PC power supply is powered on). I made two versions of this circuit: One with a (cheap) electromagnetic relay and one with an (more expensive) solid state electronic relay.

Important: The LED D3 and the surrounding components (R1, C2, D2) are not needed for the schematic to work and can easily be left out or replaced by a 110V (US version) or 220VAC (European version) neon lamp.

220V Pump switch with electromagnetic relay	110V Pump switch with electromagnetic relay
Download Schematic in Circuitmaker2000 format	Download Schematic in Circuitmaker2000 format

The PCB layout	The component layout
Download PCB layout in Circad'98 format

Internal view of the finished project

Outside view

Mounted in my PC-70

- With solid state relay:

The used solid state relay is a CX240D5 from Crydom and ordered from Digikey. It is rated for up to 5 Amps and 280VAC. The control voltage can vary from 3 to 15VDC.

There's one drawback: The minimum load current of the CX240D5 must be at least 60mA, in our case this is the sum of the pump current and the led current. The led current is about 20mA, so the pump must draw at least 40mA (under 110 or 220V).

To calculate the pump current: Pump current (Amps) = Pump power (Watts) / Mains Voltage (V)

For my Eheim 1250 pump this gives us: 28W/220V = about 127mA

For a european Eheim 1046 at 220V the pump current is 23mA, too little for the CX240D5. For a US 110V Eheim 1046 the current will be 45mA which is just fine.

220V Pump switch with solid state relay	110V Pump switch with solid state relay
Download Schematic in Circuitmaker2000 format	Download Schematic in Circuitmaker2000 format

The PCB layout	The component layout
Download PCB layout in Circad'98 format

The solder side

The component side

View from other side

Further pictures of the Solid State Pumprelay will follow soon...