20-04-2011, 06:02 PM
Maplin still do a variac - it's 0.75 Amps, which should suffice for just about any domestic radio. It's £45.00, inc VAT, post free, and can be found at this link:
http://www.maplin.co.uk/0.75a-variable-transformer-6476
As with most variacs on 240 Volts, the range of adjustment is from 0 - 270V - I can't recall the technical reason for the upper limit going beyond 240V. The spec for the Maplin one is:
0.75A
Output AC 0 to 270 V
Dimensions:
90(h) x 84(dia.) x 97(l) mm
2 x 4mm holes on 28mm PCD,
8mm hole for shaft
90(h) x 84(dia.) x 97(l) mm
2 x 4mm holes on 28mm PCD,
8mm hole for shaft
It is uncased, but has a dial, which not all variacs do, but then if you build it into a case, you can add a voltmeter and current meter if desired, which makes sense, because the point of a variac is to monotor what's happening to the equipment you are working on as you bring the voltage up to the operating voltage.
Variacs regularly crop up on e-bay - for example, there's a 2.75 Amp one at htis link, with a Buy Now price of £35.00 which seems reasonable to me, but it's £9.00 postage.
However, the spec looks a bit odd, because it states
• 2.75 AMP VARIAC
• Input 283v max 47hz
• 0 to 240v output @ 2.75amp
That doesn’t make sense – why would a variac operate on such a precise non-standard input voltage such as 283 Volts at 47 Hz, and if it did, why would it only provide 240V output? They’re questions that would need to be answered by the seller of course, (who has seven available).
http://cgi.ebay.co.uk/VARIABLE-TRANSFOME...6331151247&rvr_id=226331151247&cguid=31fe42fd12c0a0e203d17651ff70e8d2
Another one here might be a better bet. Brand new, (more than ten available) 'Buy Now' price £53 inc VAT and Postage.
Description:
3 Amp Variac, Open Type
Variable Transformer, Open Type, Single Phase, 3A, 240V, (3F-1) This variac gives a continuously variable alternating current (a.c.) output voltage, has a solid construction, high efficiency/excellent regulation and no waveform distortion with smooth linear output & overload capacity. Complete with knob, dial and screw terminals, maker, Ravi Electricals, 3F-1
http://cgi.ebay.co.uk/Variable-Transform...upplies_ET&hash=item5197dca382
Hope that helps.
David
http://www.maplin.co.uk/0.75a-variable-transformer-6476
As with most variacs on 240 Volts, the range of adjustment is from 0 - 270V - I can't recall the technical reason for the upper limit going beyond 240V. The spec for the Maplin one is:
0.75A
Output AC 0 to 270 V
Dimensions:
90(h) x 84(dia.) x 97(l) mm
2 x 4mm holes on 28mm PCD,
8mm hole for shaft
90(h) x 84(dia.) x 97(l) mm
2 x 4mm holes on 28mm PCD,
8mm hole for shaft
It is uncased, but has a dial, which not all variacs do, but then if you build it into a case, you can add a voltmeter and current meter if desired, which makes sense, because the point of a variac is to monotor what's happening to the equipment you are working on as you bring the voltage up to the operating voltage.
Variacs regularly crop up on e-bay - for example, there's a 2.75 Amp one at htis link, with a Buy Now price of £35.00 which seems reasonable to me, but it's £9.00 postage.
However, the spec looks a bit odd, because it states
• 2.75 AMP VARIAC
• Input 283v max 47hz
• 0 to 240v output @ 2.75amp
That doesn’t make sense – why would a variac operate on such a precise non-standard input voltage such as 283 Volts at 47 Hz, and if it did, why would it only provide 240V output? They’re questions that would need to be answered by the seller of course, (who has seven available).
http://cgi.ebay.co.uk/VARIABLE-TRANSFOME...6331151247&rvr_id=226331151247&cguid=31fe42fd12c0a0e203d17651ff70e8d2
Another one here might be a better bet. Brand new, (more than ten available) 'Buy Now' price £53 inc VAT and Postage.
Description:
3 Amp Variac, Open Type
Variable Transformer, Open Type, Single Phase, 3A, 240V, (3F-1) This variac gives a continuously variable alternating current (a.c.) output voltage, has a solid construction, high efficiency/excellent regulation and no waveform distortion with smooth linear output & overload capacity. Complete with knob, dial and screw terminals, maker, Ravi Electricals, 3F-1
http://cgi.ebay.co.uk/Variable-Transform...upplies_ET&hash=item5197dca382
Hope that helps.
David
