[John Walker]

Can anyone tell me where I can order a 24v DC power supply. 

I need it for my R.O. auto cut-off system that I have ordered from Ro-Man.

Ro-Man tell me I need 24v at 2amps DC to power the solenoid.

Some of the power supplies I've seen are rated at 24 volt   xxxx watts.  How many watts is 2 amp at 24v. 

Long time since my science classes 

[GWCS]

go into maplins and ask they will tell you what you need.

[jeff1]

Basics

You cannot convert watts to amps, since watts are power and amps are coulombs per second (like converting apples to miles). If you have at least least two of the following three: amps, volts and watts then the missing one can be calculated. Since watts are amps multiplied by volts, there is a simple relationship between them.
However, In some engineering disciplines the volts are more or less fixed, for example in house wiring, automotive wiring, or telephone wiring. In these limited fields they often have charts that relate amps to watts and this has confused people. What these charts should be titled is "conversion of amps to watts at a fixed voltage of 110 volts" or "conversion of watts to amps at 13.8 volts," etc.

[John Walker]

Basics

You cannot convert watts to amps, since watts are power and amps are coulombs per second (like converting apples to miles). If you have at least least two of the following three: amps, volts and watts then the missing one can be calculated. Since watts are amps multiplied by volts, there is a simple relationship between them.
However, In some engineering disciplines the volts are more or less fixed, for example in house wiring, automotive wiring, or telephone wiring. In these limited fields they often have charts that relate amps to watts and this has confused people. What these charts should be titled is "conversion of amps to watts at a fixed voltage of 110 volts" or "conversion of watts to amps at 13.8 volts," etc.

Wow!!   

Thanks Jeff

I seem to recall an equation from school days now - something like V over I R  .

I can work it out now - Cheers

[John Walker]

go into maplins and ask they will tell you what you need.

Thanks  GWCS

Will ring them later - Cheers 

[jeff1]

Basics

You cannot convert watts to amps, since watts are power and amps are coulombs per second (like converting apples to miles). If you have at least least two of the following three: amps, volts and watts then the missing one can be calculated. Since watts are amps multiplied by volts, there is a simple relationship between them.
However, In some engineering disciplines the volts are more or less fixed, for example in house wiring, automotive wiring, or telephone wiring. In these limited fields they often have charts that relate amps to watts and this has confused people. What these charts should be titled is "conversion of amps to watts at a fixed voltage of 110 volts" or "conversion of watts to amps at 13.8 volts," etc.

Wow!!   

Thanks Jeff

I seem to recall an equation from school days now - something like V over I R  .

I can work it out now - Cheers

V= Voltage  I= Current &  R= Resistance