# energizing fans

Discussion in 'General Electronics Discussion' started by woodzer, Jan 8, 2016.

1. ### woodzer

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0
Jan 8, 2016
hello all, I'm a newbie here. I have a question I hope can be answered easily. I need to energize a 20a 115v duplex with a low voltage momentary switch and time out the circuit at 5 minutes. It is for a child's project, hence the low voltage start switch. There are two small fans that need to run for 5 minutes at a time. Thank you in advance

2. ### Harald KappModeratorModerator

9,852
2,083
Nov 17, 2011
On the low voltage side it requires 12V power (not inclded), on the high voltage side it can switch up to 2.5A at 110 V (AC).

Take care of proper insulation, a suitable platsic housing is recommended on their website. A pushbutton is also separately required.

3. ### woodzer

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Jan 8, 2016
Thank you, that is the direction I need to go, although I need more amps on the 115v end. I will be operating two blower fans at the same time, so will need start up amps. I figure 20a at 115v.
Guten morgen.

4. ### Harald KappModeratorModerator

9,852
2,083
Nov 17, 2011
What kind of fans are you using? 2kW for a child's project?

Anyway, you can use an additional relay which is controlled by the timer board's relay (use 12V coil also) and which has the required amps on the contact side. Here's a collection of a few examples.

Guten Abend

5. ### woodzer

3
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Jan 8, 2016
Again, thank you. Are you familiar with air hockey, this is basically what I'm doing. We are using two 1/16 HP fans that can use up to 10a each. I need to set up for a child to switch on with a momentary and the fans to operate for five minutes, then shut down.

danke schön

6. ### BobK

7,680
1,685
Jan 5, 2010
Since 1 HP is 745W, your fans should be somewhere around 745/16 = 46W. And you say they take 10A at 115V = 1150W? That is quite an inefficient fan. Are you sure is not 1.0A?

Bob