"Standard" EIC power input vs. Filtered EIC - Page 2

Petter · 16th May 2001, 02:30 PM

Inrush current will typically always be in the 100 amps or more for a good amp. This is not the way to rate your filters ...

Thermistors work great unless you turn off, then almost immediately on, when the thermistors are still hot (but then you would still have some charge on your caps.

Petter

arnach · 17th May 2001, 03:56 AM

Use thermistors!

promitheus · 17th May 2001, 11:31 AM

Is there a way to choose a thermistor for a given toroid power rating ? I asked once a toroid constructor but he told me they choose it by practice.

Eric · 17th May 2001, 01:21 PM

I'm curious to know what ratings to choose for a thermistor given a certain transformer size also...

Petter · 17th May 2001, 10:27 PM

Thermistors are the el-cheapo way out. BAT VK60 has 5 ohm version for 110V and 10 ohm version for 220V -- they come in various sizes and get very hot. Why el-cheapo? Because you always have an extra pass element with finite resistance and you also have heat generation, might not work right if power fails, you don't know if it is broken or not (high temp usually means shorter life).

Check out the size on http://www.balanced.com ... compare with Plitron units at http://www.plitron.com.

However, it will vary with type of rectification/filtering and output voltage.

You can buy a resistive kit from http://www.lcaudio.com/tilb.htm -- 330 ohms for 3 seconds, probably OK with half the resistance for US. Nice, I might just get a couple but they are not free.

Petter

promitheus · 17th May 2001, 10:34 PM

I still think the easiest way to keep inrush current low on turn on is with in series resistors with a timer relay. There are circuits without transformet or power supply direkt from the mains supply.

Petter · 18th May 2001, 09:31 AM

The easisest and cheapest is thermistor -- a series element, hooks up like a resistor, looks like a ceramic capacitor and does not overheat which a resistor could likely do.

It is not the best, though.

17th May 2001, 03:56 AM	#12
arnach diyAudio Member Join Date: Apr 2001 Location: USA	Yes! Use thermistors!

17th May 2001, 01:21 PM	#14
Eric diyAudio Member Join Date: Nov 2000 Location: Central PA, USA	Thermistor Ratings I'm curious to know what ratings to choose for a thermistor given a certain transformer size also...

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Using a standard pentode-tetrode as output "space-charge tube" any ideas-experiences?	bembel	Tubes / Valves	12	11th March 2010 05:56 AM
"A standard CD player outputs signal at 24V"	wwenze	Digital Source	16	13th July 2009 04:50 PM
What Does Fostex "Rated Input" and "Music Power"	mark02131	Full Range	3	2nd January 2007 08:31 PM
Fostex "rated input" and "music power"	hugz	Full Range	12	16th March 2006 04:33 PM
cheap 6" or 8" woofer to make great bass for a standard cab pick up	zuki	Subwoofers	12	15th February 2005 07:54 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

16th May 2001, 02:30 PM	#11
Petter diyAudio Member Join Date: Jan 2001 Location: Scandinavia	Inrush current will typically always be in the 100 amps or more for a good amp. This is not the way to rate your filters ... Thermistors work great unless you turn off, then almost immediately on, when the thermistors are still hot (but then you would still have some charge on your caps. Petter

17th May 2001, 11:31 AM	#13
promitheus diyAudio Member Join Date: Jan 2001 Location: Germany	Is there a way to choose a thermistor for a given toroid power rating ? I asked once a toroid constructor but he told me they choose it by practice.

17th May 2001, 10:27 PM	#15
Petter diyAudio Member Join Date: Jan 2001 Location: Scandinavia	Thermistors are the el-cheapo way out. BAT VK60 has 5 ohm version for 110V and 10 ohm version for 220V -- they come in various sizes and get very hot. Why el-cheapo? Because you always have an extra pass element with finite resistance and you also have heat generation, might not work right if power fails, you don't know if it is broken or not (high temp usually means shorter life). Check out the size on http://www.balanced.com ... compare with Plitron units at http://www.plitron.com. However, it will vary with type of rectification/filtering and output voltage. You can buy a resistive kit from http://www.lcaudio.com/tilb.htm -- 330 ohms for 3 seconds, probably OK with half the resistance for US. Nice, I might just get a couple but they are not free. Petter

17th May 2001, 10:34 PM	#16
promitheus diyAudio Member Join Date: Jan 2001 Location: Germany	I still think the easiest way to keep inrush current low on turn on is with in series resistors with a timer relay. There are circuits without transformet or power supply direkt from the mains supply.

18th May 2001, 09:31 AM	#17
Petter diyAudio Member Join Date: Jan 2001 Location: Scandinavia	The easisest and cheapest is thermistor -- a series element, hooks up like a resistor, looks like a ceramic capacitor and does not overheat which a resistor could likely do. It is not the best, though.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)