Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > The Doctor is In! > Ask the Doctor
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 12-08-2010, 01:15 AM
blackshire's Avatar
blackshire blackshire is offline
Master Modeler
 
Join Date: Jan 2009
Location: Fairbanks, Alaska
Posts: 6,507
Default Compressor plug question

Hello Doctor,

I recently bought an airbrush set (including a 50 Hz/60 Hz compressor) for friends of mine at the Northcote Heavy Horse Centre www.northcotehorses.com in England, for their model rocketry activities for their visitor days. I also got a 240 volt/120 volt converter to enable the compressor's 120 volt "wall wart" power supply transformer to work with their local 240 volt electric service. There are three unknowns and one problem with this set-up, which are:

[1] The 220 volt/120 volt converter has two switch-selectable output wattage levels--50 watts and 1600 watts (the latter is intended for high-resistance units like hair dryers). The airbrush compressor only draws 72 watts, so would using the 1600 watt setting overheat the converter?

[2] If the answer to [1] is "NO," because of the large difference between the converter's 1600 watt output and the compressor's 72 watt draw (which is only intermittent anyway, when the compressor and airbrush are used), should the 240 volt/120 volt converter be unplugged from the 240 volt wall socket when the compressor is not in use?

[3] On the input side of the converter, the UK plug can be slid onto the converter's round prongs in either of two ways (and the UK wall plug's prongs aren't polarized like those in most US wall plugs). Does this mean that the UK plug's orientation on the converter's prongs doesn't matter? (In either orientation, the UK wall plug's "hot" prongs are oriented 90 degrees to the long dimension of the converter case.)

[4] The converter's 120 volt output socket (which *is* polarized to accept polarized US wall plugs) is quite loose, with the spring metal strips inside the socket barely making contact with the prongs of the compressor's "wall wart" power supply. (All of the other appliance plugs around my apartment fit in it loosely, too. The converter is brand-new, and was made in China. I suspect they're all loose.) The case has no screws and can't be opened without breaking it. Would wrapping strips of aluminum foil around the "wall wart's" prongs (to ensure that they fit snugly in the converter's 120 volt output socket and make good electrical contact) be safe? (Since this is a dedicated set-up, the "wall-wart" will never be unplugged from the converter as long as either one lasts.)

Many thanks in advance to anyone who can help!
__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

Last edited by blackshire : 12-08-2010 at 01:28 AM. Reason: This ol' hoss done forgot somethin'.
Reply With Quote
  #2  
Old 12-08-2010, 07:26 AM
jeffyjeep's Avatar
jeffyjeep jeffyjeep is offline
Old Submariner
 
Join Date: Jan 2009
Location: Home of Wayne & Garth
Posts: 7,760
Default

I think I can answer some--but not all--of your questions.

1) It's same to use the higher wattage setting for a lower wattage application. Just DON'T use lower wattage setting for a high wattage application. The application will only draw the watts it requires.

2) On a UK plug, the "3rd" leg is ground. The other two aren't polarized.

3) A couple things to be aware of: since UK uses 240 VAC 50HZ, make sure the compressor can run on 120VAC 50HZ. The converter will step down the voltage, but probably not the waveform.

4)CAUTION: if the compressor has any electronic components (circuit board, digital display, electronic timer) you probably cannot use the converter--it will burn the converter up.
__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078
Reply With Quote
  #3  
Old 12-08-2010, 09:06 AM
blackshire's Avatar
blackshire blackshire is offline
Master Modeler
 
Join Date: Jan 2009
Location: Fairbanks, Alaska
Posts: 6,507
Default

Quote:
Originally Posted by jeffyjeep
I think I can answer some--but not all--of your questions.

1) It's same to use the higher wattage setting for a lower wattage application. Just DON'T use lower wattage setting for a high wattage application. The application will only draw the watts it requires.

2) On a UK plug, the "3rd" leg is ground. The other two aren't polarized.

3) A couple things to be aware of: since UK uses 240 VAC 50HZ, make sure the compressor can run on 120VAC 50HZ. The converter will step down the voltage, but probably not the waveform.

4)CAUTION: if the compressor has any electronic components (circuit board, digital display, electronic timer) you probably cannot use the converter--it will burn the converter up.


Thank you very much, jeffyjeep! I specifically chose this compressor (this airbrush & compressor set is available on eBay for just $51.95 + $9.95 for postage, see: http://cgi.ebay.com/ws/eBayISAPI.dl...c%253D&viewitem ) because it can run on either 50 Hz or 60 Hz AC power (I also got one for myself). The compressor's "wall-wart" power supply transformer is actually rated for 100 volts AC - 240 volts AC input, but because it is quite small physically I figured the 240 volt/120 volt converter would "ease its burden," so to speak. The compressor has no fancy electronic gazortenplatzes on it, just an ON/OFF button switch. If I "pinch" the "wall-wart's" prongs inward toward each other slightly, they should fit snugly in the converter's 120 volt AC output socket.
__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR
Reply With Quote
  #4  
Old 12-08-2010, 09:15 AM
jeffyjeep's Avatar
jeffyjeep jeffyjeep is offline
Old Submariner
 
Join Date: Jan 2009
Location: Home of Wayne & Garth
Posts: 7,760
Default

It looks like you got it for a good price. It wasn't.............


wait for it.........................


wait for it.......................


wait for it..........................


wait for it...................


wait for it.......................


"inflated".

Thank you. I'll be here all year.
__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078
Reply With Quote
  #5  
Old 12-08-2010, 09:41 AM
blackshire's Avatar
blackshire blackshire is offline
Master Modeler
 
Join Date: Jan 2009
Location: Fairbanks, Alaska
Posts: 6,507
Default

Quote:
Originally Posted by jeffyjeep
It looks like you got it for a good price. It wasn't.............


wait for it.........................


wait for it.......................


wait for it..........................


wait for it...................


wait for it.......................


"inflated".

Thank you. I'll be here all year.
That's *precisely* why I chose to buy them now rather than later! :-)
__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -5. The time now is 06:18 AM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe © 1998-2024