yeah, won't open for me either.
It was posted as a local link from his hard drive, not accessable from the web.
Please post it again on the web, as I am interested in your idea.
--
Brian
gte619j@prism.gatech.edu
It was posted as a local link from his hard drive, not accessable from the web.
Please post it again on the web, as I am interested in your idea.
--
Brian
gte619j@prism.gatech.edu
Even simple things might turn out wrong.
Please check once more
Current limiter once more
I have used this metode one a pair of homemade Futterman OTL3e with 1000W transformers for more then 10years.
You might have to play a little around with the value of the resistor.
Claus
Please check once more
Current limiter once more
I have used this metode one a pair of homemade Futterman OTL3e with 1000W transformers for more then 10years.
You might have to play a little around with the value of the resistor.
Claus
Excellent!
I use kristijan's schematic, from elektor elektronics, for some years now and i am absolutely happy with it as i also use it in my aleph.
In comparison with simpler ones the gain is that u do not have to use super duper heavy mains switches as the main current goes through the first relay and it never fails. (i also have designed the dedicated pcb in case that somebody needs it).
Regards,
Panos
I use kristijan's schematic, from elektor elektronics, for some years now and i am absolutely happy with it as i also use it in my aleph.
In comparison with simpler ones the gain is that u do not have to use super duper heavy mains switches as the main current goes through the first relay and it never fails. (i also have designed the dedicated pcb in case that somebody needs it).
Regards,
Panos
Hi Steve,
I would strongly recommend using some kind of softstart (even an NTC) cause every switch will brake eventually. I tried to switch two 500VA transformers without but every relais I used (up to 40A rated) was eventually destroyed. Now I use a 100 ohms resistor for 4 seconds and have absolutely no problems.
in selecting an inductor it depends on the space you have available and the money you want to spend. Even a small inductor will reduce the ripple a lot. I´ve bought 4 1.8mH/0.38Ohms inductors (1.4mm). These will reduce the ripple voltage from almost a volt to about 10mV @ 2A. I use 40mF before and 66mF after the inductor.
william
I would strongly recommend using some kind of softstart (even an NTC) cause every switch will brake eventually. I tried to switch two 500VA transformers without but every relais I used (up to 40A rated) was eventually destroyed. Now I use a 100 ohms resistor for 4 seconds and have absolutely no problems.
in selecting an inductor it depends on the space you have available and the money you want to spend. Even a small inductor will reduce the ripple a lot. I´ve bought 4 1.8mH/0.38Ohms inductors (1.4mm). These will reduce the ripple voltage from almost a volt to about 10mV @ 2A. I use 40mF before and 66mF after the inductor.
william
DELAY
Dear Fcel,
Sorry for the "delay" but I had to convert the file to pdf in order to post it here and then zip it.
The zipped file contains the mask and the pcb file of the schematic kristjan posted earlier in the thread.
Please note that the component values shown in my files are intented for 110Volts AC as I presume u are located in US.
The relays in use are 24V 10A with dual contacts wired in parallel.
B1 is a generic rectifier specified around 50V/1,5A.
For 220V-240V operation there should be a minor change in the values of C1, C2 as well as R1 as shown in kristjan's schematic.
Regards,
Panos
Dear Fcel,
Sorry for the "delay" but I had to convert the file to pdf in order to post it here and then zip it.
The zipped file contains the mask and the pcb file of the schematic kristjan posted earlier in the thread.
Please note that the component values shown in my files are intented for 110Volts AC as I presume u are located in US.
The relays in use are 24V 10A with dual contacts wired in parallel.
B1 is a generic rectifier specified around 50V/1,5A.
For 220V-240V operation there should be a minor change in the values of C1, C2 as well as R1 as shown in kristjan's schematic.
Regards,
Panos
Relays
Panos,
I have followed the PCB layout from your zip file and get most of the parts, except the relays and the switch, the guy at the shop did not have the 24V 10A ones, and he wondered whether it was AC or DC that I was talking about. Of course I have no clue being
new to this DIY hobby.
They do not have the 680n/400V, so I will use two 0.33uf/400V in parallel, is that OK?
I also could not figure out where C1 and you have S1,S2 and S3 in compare with the schematic from Kristijan last posted.
If you don't mind post the parts name or something. It is for the JLH class A for ELS version in Canada 115 V ac.
Thanks,
Chris
Panos,
I have followed the PCB layout from your zip file and get most of the parts, except the relays and the switch, the guy at the shop did not have the 24V 10A ones, and he wondered whether it was AC or DC that I was talking about. Of course I have no clue being
new to this DIY hobby.
They do not have the 680n/400V, so I will use two 0.33uf/400V in parallel, is that OK?
I also could not figure out where C1 and you have S1,S2 and S3 in compare with the schematic from Kristijan last posted.
If you don't mind post the parts name or something. It is for the JLH class A for ELS version in Canada 115 V ac.
Thanks,
Chris
Canadian Delay
O.K
Dear Chris,
Using C2=2X330nf in parallel will be o.k, C1 is not needed for 115VAC.
About the relay now I believe any relay with dual contacts will do,
as far as the contacts are rated to about 5-10A.
About the voltage of the coil now should be 24VDC and this is very common among relays for pcb use.
S1, S2 ans S3 are simply 3 small switches wired in series, with adequate insulation for 115Vac (no need for heavy duty as the current through these is very small, 200mA or so).
The reason why I use 3 is because in my amp I use a switch and two thermal breakers rated at 70 degrees Celsius in order to provide power supply cutoff in case of big thermal increase on my 2 heatshinks. If u do not need this, u can jumper S1 and S2 and use S3 for the switch.
Regards,
Panos
O.K
Dear Chris,
Using C2=2X330nf in parallel will be o.k, C1 is not needed for 115VAC.
About the relay now I believe any relay with dual contacts will do,
as far as the contacts are rated to about 5-10A.
About the voltage of the coil now should be 24VDC and this is very common among relays for pcb use.
S1, S2 ans S3 are simply 3 small switches wired in series, with adequate insulation for 115Vac (no need for heavy duty as the current through these is very small, 200mA or so).
The reason why I use 3 is because in my amp I use a switch and two thermal breakers rated at 70 degrees Celsius in order to provide power supply cutoff in case of big thermal increase on my 2 heatshinks. If u do not need this, u can jumper S1 and S2 and use S3 for the switch.
Regards,
Panos
You have to use a thermistor like Pass uses in the aleph series to reduce the inrush current. At normal function the switch should handle 1-3 amps for 220 V or 2-6 for 110 V. As some said before you will have a much bigger problem with the house fuse or breaken anyway. You can´t do without an inruch current limiter any way. You can get away with it if you have a toroid with less then 300 VA power rating.
My last project the 1996 version of the JLH used one switch to control two 300VA Tor.transformers in one box with no problem. Sure the lights in the room dimmed for a fraction of a second when I switched the amp on. But otherwise everything seems ok. The switch I bought from Home Depot rated for 15amp normal house hold toggle switch. But soft start is the way I am going this time just to be safe rather than sorry.
Velleman KT4700
Panos,
I've made the PCB from you zip file and got all the parts. I had to modify it a little bit in order for the power resistors have enough room to get on the PCB. Also the relay I bought are slightly thinner than the ones on the PCB. All ready for light up the solder iron.
But this morning I came across this KT4700 speaker protection kit. I would like to use this one as well for its DC protection feature. But it seems it also has a delay start function. Do you think I can use the soft start made acording to you zip file in combination with this kit together.
Vellman actualy has another KT4701 in-line just the DC speaker protection kit which mount between the speaker leads in the speaker housing.
ChrisPlease comment
Panos,
I've made the PCB from you zip file and got all the parts. I had to modify it a little bit in order for the power resistors have enough room to get on the PCB. Also the relay I bought are slightly thinner than the ones on the PCB. All ready for light up the solder iron.
But this morning I came across this KT4700 speaker protection kit. I would like to use this one as well for its DC protection feature. But it seems it also has a delay start function. Do you think I can use the soft start made acording to you zip file in combination with this kit together.
Vellman actualy has another KT4701 in-line just the DC speaker protection kit which mount between the speaker leads in the speaker housing.
ChrisPlease comment
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