Puroy56
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« on: May 13, 2009, 10:29:51 AM » |
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Hello guys!
When browsing the internet I always come across Transformer ratings as say, 150VA or 180VA. How do you translate this? Kasi dito sa pinas, pagbibili ka ng transformer o pagagawa ka sasabihin mo lang kung ano ang voltage ng primary at secondary tapos yung ampere rating nito. Papano ba i-convert ito kung rated nga ang transformer sa 150VA? Ilang Amperes lalabas ito kung 220v ang mains mo?
Meron din instance na ang transformer ay rated as, say 200watts/25-0-25v, papano din kaya ito? Ilan amperes din kaya dapat lalabas ito?
Pls. help guys. Thanks.
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The Philippine Electronics and Technology Forum
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« on: May 13, 2009, 10:29:51 AM » |
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ian23jess
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« Reply #1 on: May 13, 2009, 02:54:40 PM » |
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sa pagkakaalam ko pag sinabing VA (Volt Amps) which is the same as Watts kunwari 350VA katumbas nito 350w ginagamit yata ang term na VA usually sa mga power supply dahil meron itong power factor circuit. which means pure 350watts ang makakaya ng isang power supply. pag watts naman ang ginagamit usually ito ung mga appliances na may resistive and capacitive load means +/- 350 watts. i mean not exactly as 350 watts talaga...  sa pagkakaalam ko ha. pero mas maganda tanong mo si wikipedia  |
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Woots29
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« Reply #2 on: May 13, 2009, 02:59:28 PM » |
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may paliwanag jan tungkol sa VA at watts
tama may kinalaman yan sa power factor
nasan ba si sir mushroom...yuhoo!!!
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rdpzycho
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« Reply #3 on: May 13, 2009, 04:57:49 PM » |
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'yung VA rating ng transformer ay 'yung output voltage ng current rating, 'yung 12V 1A = 12VA. madalas undersized ang ibang transformers kaya dapat nagbibigay ng allowance. may mga makikita kang amplifier design na ilang watts lang pero malaki ang headroom sa transformer. kailangan din kasi i-consider 'yung power factor ng supply, rectifier plus capacitor nasa 0.6 ang range ng PF, IIRC. mas maganda ng mag-overrate ng malaking factor (for your own projects) kaysa underrated.  kapag commercial naman merong mga compromises, at madalas nasa optimum point na balanced ang price, size, at performance. |
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"Keep on starting, and finishing will take care of itself."
- Neil Fiore
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fredmontano
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« Reply #4 on: May 19, 2009, 02:10:28 PM » |
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me tanong lang rin ako na medyo related so ibig sabihin ba na pag meron akong trafo na 18-0-18 ang secondary and 6 amps ang rating does it follow na 108 VA ang transformer rating (18x6)? and 3 amps on +18 and 3 amps on -18?
Thanks sa mga sasagot na mga masters tungkol dito.
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TinTopHack
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« Reply #5 on: May 30, 2009, 12:05:14 AM » |
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Kung 18-0-18 @ 6A yan, it should be 18 x 6 x 2 or 36 x 6 = 216VA
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The world, as everybody knows, is analog; unless, of course, it's digitized.
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wojou
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« Reply #6 on: July 06, 2010, 08:18:50 AM » |
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Problem: PWMPS no output voltage. Hindi nakakapag trigger/ no output ung PWM.
Process: Input ACV ---> choke coil ---> filter coil ---> controller ---> PWM w/ standby voltage of 300V (UC3825DW) ---> coil ---> MOSFET (W15NA50) ---> primary coil of the transformer ---> secondary coil of the transformer ---> MOSFET's ---> Output voltage.
Note: bali ung controller eh ung feedback ng PWM.
tnx.
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wojou!
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tony
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« Reply #7 on: November 28, 2010, 11:11:31 AM » |
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Hello guys!
When browsing the internet I always come across Transformer ratings as say, 150VA or 180VA. How do you translate this? Kasi dito sa pinas, pagbibili ka ng transformer o pagagawa ka sasabihin mo lang kung ano ang voltage ng primary at secondary tapos yung ampere rating nito. Papano ba i-convert ito kung rated nga ang transformer sa 150VA? Ilang Amperes lalabas ito kung 220v ang mains mo?
Meron din instance na ang transformer ay rated as, say 200watts/25-0-25v, papano din kaya ito? Ilan amperes din kaya dapat lalabas ito?
Pls. help guys. Thanks.
VA ratings pertains to primary so a traffo rated 180va at 220 volts will have primary current at 180/220 or 0,8amps..... not all of the primaries' VA rating can be converted to sencondary power, remember that we have to consider copper losses and iron losses...so much so that a primary va rating needs to be derated at 70%, especially for small transformers, (less than 1000va) |
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in electronics, as in everyday life, there is always a reason for doing things...and if you can not explain why you want to do what you are about to do, better stop or else magic smoke will come out, safety first is the best policy here.....kuha mo?
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tony
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« Reply #8 on: November 28, 2010, 11:39:41 AM » |
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me tanong lang rin ako na medyo related so ibig sabihin ba na pag meron akong trafo na 18-0-18 ang secondary and 6 amps ang rating does it follow na 108 VA ang transformer rating (18x6)? and 3 amps on +18 and 3 amps on -18?
Thanks sa mga sasagot na mga masters tungkol dito.
216 watts sa secondary so that means yor traffo needs to be rated at 300 VA.... |
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in electronics, as in everyday life, there is always a reason for doing things...and if you can not explain why you want to do what you are about to do, better stop or else magic smoke will come out, safety first is the best policy here.....kuha mo?
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ghomer
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« Reply #9 on: January 07, 2011, 01:17:55 PM » |
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question po.. pwde po ba parewing yung traffo ko, rated at 50v 0 50v 20 ampere..na sobrang bigat.
may amp is westrak, gusto ko kasi ma-achieve yung 500watts into 8ohms.. my filter cap 2x75vdc 17000uf.
pwde po ba perwind yung taffo ko??? ilang volts po ba para sa 500watts??
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tony
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« Reply #10 on: January 07, 2011, 02:58:55 PM » |
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ano yan 250 watts per channel 8 ohms kaya naging 500 watts? kasi kung 75 volts lang ang capacitor mo hindi ka makakakuha ng 500 kahit gaano kabigat yung traffo mo...
to get 250 watts into 8 ohms kailangan ng amp mo na mag-output ng 45volts rms sa 8 ohms load......
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in electronics, as in everyday life, there is always a reason for doing things...and if you can not explain why you want to do what you are about to do, better stop or else magic smoke will come out, safety first is the best policy here.....kuha mo?
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pete
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« Reply #11 on: January 21, 2011, 10:37:03 PM » |
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subscribing...........
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CASTILLO ELECTRONICS
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dyiez10
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**Not After all IMPOSSIBLE**
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« Reply #12 on: February 05, 2011, 02:08:20 PM » |
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anggaling nyo na po. Hehe, gusto ko narin magwork at maiaply mga nttunan ko sa school.
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