0
\$\begingroup\$

First of all, I'm a newbie in electronics, please be patient with me.

My problem is that I want to use a pump for a project, a ulka model e type ep5. I salvaged it from an old coffee machine.

It had no power supply, was directly plugged to the wall, and I don't want to put myself in danger.

How could I use it with a lower voltage/without plugging it directly into the wall?

\$\endgroup\$
  • \$\begingroup\$ Something is getting lost in translation I think... al·i·men·ta·tion /ˌaləmənˈtāSH(ə)n/ nounformal noun: alimentation the provision of nourishment or other necessities of life. \$\endgroup\$ – J. Raefield Apr 15 at 19:44
  • \$\begingroup\$ @J.Raefield exactly: i meant power supply \$\endgroup\$ – Orsu Apr 15 at 19:54
  • \$\begingroup\$ It is a vibratory pump from an espresso machine. I don't think you can run it at any different voltage. From the datasheet, I see that there is an EP5D model rated for 24V. But I assume that you are not looking to buy a new one. There could be some slight chance that you could find the motor winding and rewire it for 24V, but it hardly seems worth it to invest that much effort in a free pump. Maybe you could control it with a relay to maintain isolation and safety. \$\endgroup\$ – mkeith Apr 15 at 19:56
0
\$\begingroup\$

Chances are that if it was designed for a particular voltage, it will not run properly at a lower voltage.

\$\endgroup\$
0
\$\begingroup\$

Nothing easier. Obtain a 120V-to-your-voltage transformer.

On the pump, put the transformer right next to the pump, wire the transformer primary (the 120V side) to the pump motor. That side of the transformer will get to 120V+, so pot the heck out of it / double insulate it so nobody can get near those connecting wires.

Then, attach your low-voltage drive circuit to the secondary of the transformer.

This is called backfeeding a transformer. (this is how jackasses with home generators kill power company linemen, by the way.)

Anyway, you drive the transformer with your voltage at 50/60 cycles AC. Now, you don't need a full-wave inverter for this. You may be able to get off as cheaply as simply pulsing DC power to the transformer at your designated frequency. Or you can do a half-wave inverter, by using a center-trap transformer at twice your voltage (only requiring two gates and no negative power). You just have to play with it and see what works.

You may also be able to do even cooler things like VFD the motor, i.e. change the frequency to start it up or regulate its flow.

\$\endgroup\$
  • \$\begingroup\$ I think that's way out of my level. Noted tho \$\endgroup\$ – Orsu Apr 15 at 21:39

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.