Re: Wow, still activity here!
Most manufacturers recommend max 220 ohm between OUT and ADJ so if you use those values you will surely get a LM317 to work properly but I notice that 1k is OK in most situations.ALW said:
Raja, my ISP can't get in touch with your mailserver. I'm not sure we have a monologue or a dialogue. I have got your emails but mine seems not to be delivered or delayed. Would you please confirm that you have got amy emails lately.Raj1 said:
my email
Hi PA,
It's probably better to use the forum to contact me, or use the email adress I'll send you. Unfortunatley I've had a lot of trouble with the ntlworld address, this is the fault of the provider.
I'll send you a PM.
Thnaks
Raja
Hi PA,
It's probably better to use the forum to contact me, or use the email adress I'll send you. Unfortunatley I've had a lot of trouble with the ntlworld address, this is the fault of the provider.
I'll send you a PM.
Thnaks
Raja
Hi,
has anyone ever tried really fast opamps in the super regulator, like the lm6171. I dare not try them, unless someone has managed to get them stable, if that is at all possible.
I do know that someone mentioned the lm6171 earlier in this thread, but Andy said he could not remember the reason why he rejected the lm6171.
Just wondered if anyone had been a bit adventurous........
Thanks
Raja
has anyone ever tried really fast opamps in the super regulator, like the lm6171. I dare not try them, unless someone has managed to get them stable, if that is at all possible.
I do know that someone mentioned the lm6171 earlier in this thread, but Andy said he could not remember the reason why he rejected the lm6171.
Just wondered if anyone had been a bit adventurous........
Thanks
Raja
I haven't tried anything faster AD825 but remember that the emitter follower sets the limit. You can't use a faster opamp than the emitter follower and I don't know where exactly the speed limit is but BD139/140 are 100 MHz and D44/45 are 40 MHz transistors. Unity gain bandwidth of AD825 is around 45 MHz.
Hi,
I'm having a hard time getting a 2.8v version of alw's board to work at a current of around 220ma. I have tried 2 differnt opamps, and I get around 2.9v on output with both, but as soon as I connect the load, the leds dimm, and the trasnformer begins to buzz.
I have used a low voltage opamp (I think el2044) and also even tried an ad825, although well out of range here, I used it at 5v fine, and I have heard peranders managed to get it working even lower.
The reference is a 1.2v regulator diode.
The transformer is 12va. I have checked all connections and components orientation on the pcb.
The transformer worked fine when I was using the lm317 as a current regulator with the same load (no buzzing), I have checked and replaced the diode bridge and everything measures fine. No blown diodes (no ac after the bridge).
any ideas??? Or could it be that I am exceeding the regulator margin at this load? I find it strange that the transformer would buzz as if it is being put under severe load.
Thanks
Raja
I'm having a hard time getting a 2.8v version of alw's board to work at a current of around 220ma. I have tried 2 differnt opamps, and I get around 2.9v on output with both, but as soon as I connect the load, the leds dimm, and the trasnformer begins to buzz.
I have used a low voltage opamp (I think el2044) and also even tried an ad825, although well out of range here, I used it at 5v fine, and I have heard peranders managed to get it working even lower.
The reference is a 1.2v regulator diode.
The transformer is 12va. I have checked all connections and components orientation on the pcb.
The transformer worked fine when I was using the lm317 as a current regulator with the same load (no buzzing), I have checked and replaced the diode bridge and everything measures fine. No blown diodes (no ac after the bridge).
any ideas??? Or could it be that I am exceeding the regulator margin at this load? I find it strange that the transformer would buzz as if it is being put under severe load.
Thanks
Raja
I have got an AD825 work with at least 3.1 volt but the most important thing is that the output of the opamp is in it's active range. I replaced the zener with a plain red LED. You must also recalculate all values of the output stage.
So...
1 Choose an opamp which safely can work with a common mode voltage from 1 volt or so.
2 Choose an opamp whoch can work properly from 2.0-2.5 volts and up. You can also do as I have done in my design, I have two feeding options for the supply voltage. In low voltage situations you can feed the opamp from the unregulated side and if you use a preregulator the opamp will still have pretty stabilized voltage.
So...
1 Choose an opamp which safely can work with a common mode voltage from 1 volt or so.
2 Choose an opamp whoch can work properly from 2.0-2.5 volts and up. You can also do as I have done in my design, I have two feeding options for the supply voltage. In low voltage situations you can feed the opamp from the unregulated side and if you use a preregulator the opamp will still have pretty stabilized voltage.
Hi Luke,
the designer of the regulator and boards ALW, you could contact him for availability. 1,5 year ago when I heard of these regs I bought 4 kits from him. I don't know if he still sells the PCB and/or kits and if he has improved the design.
Regards Henk
PS a quick search in the member list showd he is 'off line' since 2nd of May 2005, hope he does read his email
the designer of the regulator and boards ALW, you could contact him for availability. 1,5 year ago when I heard of these regs I bought 4 kits from him. I don't know if he still sells the PCB and/or kits and if he has improved the design.
Regards Henk
PS a quick search in the member list showd he is 'off line' since 2nd of May 2005, hope he does read his email
Still alive...
...just really busy!
I'm considering organising another group buy, should there be sufficient interest, as it requires less work to organise one big group buy than lots of individual emails, which I can honestly say I'm struggling to keep up with at present and my stocks are almost exhausted!
It will be hosted via the Pink Fish Media forum at www.pinkfishmedia.net/forums, so keep an eye out there for posts from 'alw Audio' and register your interest when the mechanism to do so is posted.
Cheers,
Andy.
...just really busy!
I'm considering organising another group buy, should there be sufficient interest, as it requires less work to organise one big group buy than lots of individual emails, which I can honestly say I'm struggling to keep up with at present and my stocks are almost exhausted!
It will be hosted via the Pink Fish Media forum at www.pinkfishmedia.net/forums, so keep an eye out there for posts from 'alw Audio' and register your interest when the mechanism to do so is posted.
Cheers,
Andy.
Hi Andy,
Im in for a couple, no hurry actually so can wait. Will you sell complete kit or boards?
Im in for a couple, no hurry actually so can wait. Will you sell complete kit or boards?
Boards only this time, or *possibly* the option to have the SOIC AD825 pre-fitted.
Depends largely on volumes / logistics but the option will be there in the register of interest.
Andy.
I am a bit stumped with this problem so please help.
The first regulator I made for 13.6v worked very well.
However the second one adjusted for 24v with r8/r9 1.8k/680 ohm does not work properly.
It draws a huge amount of current around 140ma and the opamp and pnp transistor get extremely hot.The voltage output is around 16v.The lm329 seems to be only at 6.3v.
Nothing is wrong with the parts or placement because when I substitute r8/r9 with 1k/1k then it seems to be working properly at 13.6 v with low current consumption.
ALW or others please help.
The first regulator I made for 13.6v worked very well.
However the second one adjusted for 24v with r8/r9 1.8k/680 ohm does not work properly.
It draws a huge amount of current around 140ma and the opamp and pnp transistor get extremely hot.The voltage output is around 16v.The lm329 seems to be only at 6.3v.
Nothing is wrong with the parts or placement because when I substitute r8/r9 with 1k/1k then it seems to be working properly at 13.6 v with low current consumption.
ALW or others please help.
Have you checked that you have turned the small signal transistors right? If you flip emitter and collector the transistor will work but max voltage will be 7-15 volts and gain of 3-10.
Remember this is a thread about a new regulator so if you don't mind start your own thread about your problem.
the regulator in question is the one presented in this thread so I thought this was the right place to post.
Excuse me, I'm mixing things 
I'll guess your problem is too low raw voltage. Minimum +5 V of the wanted output voltage. That is true if you use the preregulator. You must have 24 VAC at least.
I'll guess your problem is too low raw voltage. Minimum +5 V of the wanted output voltage. That is true if you use the preregulator. You must have 24 VAC at least.
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