Yeh, was originally thinking of using the supplies for the lme's and building an un-regulated supply for the fets, but along came the dps-600 in a nice'n'tidy package 🙂
I need to build one supply at +/- 15V for a second Wire se-se that's to act as a pre & headphone section for this one. I'd also like to build the second (purely for testing) at +/- 20V or 25V, probably the latter.
I do think I've missed a trick here, now wishing I'd got enough bit's to build a 5 channel amp for my home cinema... any how, what I've got will be well used.
I need to build one supply at +/- 15V for a second Wire se-se that's to act as a pre & headphone section for this one. I'd also like to build the second (purely for testing) at +/- 20V or 25V, probably the latter.
I do think I've missed a trick here, now wishing I'd got enough bit's to build a 5 channel amp for my home cinema... any how, what I've got will be well used.
Hi,
Today for me is a hot day (not only for the 40 ° ambient) I refer to the "logistics" of these shipments.
for the bias, if the amp has no errors, is simple as said before. When I make the first start on a new project, I put 22R 10W resistors in series, one on each side. This helps me to have the time to understand.. 🙂
regards
Today for me is a hot day (not only for the 40 ° ambient) I refer to the "logistics" of these shipments.
for the bias, if the amp has no errors, is simple as said before. When I make the first start on a new project, I put 22R 10W resistors in series, one on each side. This helps me to have the time to understand.. 🙂
regards
The above is a good idea, and there are a variety of things you can do in the same ballpark.
The whole idea is that if you did something badly wrong (solder bridge shorting V+ to GND or something like that) you don't want to destroy your PSU or your amp. The following works well for this:
- Fuses : At the very least, add a fast-blow fuse at 2-3A on both V+ and V-
- Resistors: As AP2 mentioned, large power resistors on V+ and V- work very well for start-up. Just monitor the voltage across them
- Multimeters : You can never have enough of these. Measure everything during startup, and set it up in advance with clip leads if possible. Nobody likes to probe a circuit that might explode at any time 🙂
- Light Bulbs : If you don't have power resistors, you can use light bulbs, but keep in mind that their resistance is actually quite low when they're cold, and increases rapidly when they get hot. They also act as a great "Current is flowing through me" visual indicator.
What makes a class AB amplifier easy to bring up, is that if you've done it correctly, there should be no current flow through the mosfets until you adjust the bias. That means if you use current limiting devices (like resistors or lightbulbs) then they won't interfere with normal operation until you start to up the bias current. That allows you to flip the switch, have good protection in place that will limit current in the event of a mistake, and then you can check the whole circuit for functionality with the protection in place. Once you're comfortable with everything, bias up to about 100mA, power down, take off the training wheels, and start back up. At this point you can set the bias to the final value, and just keep checking it from time to time as the amp warms up to final operating temp. Bias is quite stable over temperature, but small adjustments might be needed if you're a little OCD like me 🙂
Cheers,
Owen
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so you dont think my tea-tray will cut it? I usually use one of those lap tables/TV dinner trays and a pair of goggles ha. i'll take some photos if people want.
i've only got 3 meters, might buy another couple cheapies.
dead shorts from V+->G are dead easy to avoid, I already know i'm clear of those. I could just see the dps600 going pretty ballistic on the amp before its protection cut in; or at least its unfamiliar enough territory that i'm not quite sure what to expect.
thanks for the list, i've got some suitable resistors and can probably rustle up some fuses.
No they aren't, your only chance is to check the swap meet subforum in the off-chance someone is selling their set.
No, some collected as lolo etc. your becouse Australia, i'm wrong time clock. i mean, some country as your, ups have two services, one collect at AM 12:30, other at PM 18:00. at 12:30 ups not find some package.
yes..seem a story infinite, i'm exaust even for real name->Nick name. why all not put even nik name? maybe is a stupid my question but i know a lot of hours for write invoice,close package and search version of dps-600 that i have GB with nick name...well, i not want ear of ragulators...forever.
Roberto:
I feel your pain! For anyone who has never organized a GB, it is genuinely an enormous quantity of work, and the smallest little things can result in hours of wasted time.
I learned the hard way that including both a real name and the diyAudio user name in the payment is an absolute must!
Glad to hear these supplies are on their way out to people.
Cheers,
Owen
I feel your pain! For anyone who has never organized a GB, it is genuinely an enormous quantity of work, and the smallest little things can result in hours of wasted time.
I learned the hard way that including both a real name and the diyAudio user name in the payment is an absolute must!
Glad to hear these supplies are on their way out to people.
Cheers,
Owen
Owen, thanks for the support, I certainly did not lose for the organization, but in this gb'm alone, my colleagues look at me and laugh hehe! maybe it's the heat, every little thing seems like a mountain.
sorry update wasnt above, but what do you mean? hochopeper is being sent with mine; you know that. sorry but this doesnt make sense, you say our box was packed and ready since friday night and only just missed fridays pickup, its now the end of wednesday, every day we have to chase you to find the information
we are now nearly 40 days since you said they were shipped, i'd say we are justified in feeling the frustration at this point when we get again the below the same since yesterday. this still is the same as last time, it still has not been picked up. i'm trying to be patient because I know how much work GB's are, but you do make it very difficult
i'll happily take this back, i'm not trying to be difficult here, but its now 7.22pm there, you say its been picked up now? or not? both 12.30 and 18.00PM have passed
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I want understand better...i not have diconnect my job on this smps from 3,5 weeks. now..lolo collected (maybe currier update at short), from today started package 3-4 at day. all you are right but..muntain is a end. just now we all have nervous?
sorry update wasnt above, but what do you mean? hochopeper is being sent with mine; you know that. sorry but this doesnt make sense, you say our box was packed and ready since friday night and only just missed fridays pickup, its now the end of wednesday, every day we have to chase you to find the information
we are now nearly 40 days since you said they were shipped, i'd say we are justified in feeling the frustration at this point when we get again the below the same since yesterday. this still is the same as last time, it still has not been picked up. i'm trying to be patient because I know how much work GB's are, but you do make it very difficult
i'll happily take this back, i'm not trying to be difficult here, but its now 7.22pm there, you say its been picked up now? or not? both 12.30 and 18.00PM have passed
Ups (18:30) can not read package for Australia. I did not know this
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Roberto, its not nervousness, its frustration and confusion. this is 3.30AM here, yes AM every day the end of the day at your end is 2AM here. i'm usually up late, so its not like i'm waiting since 10pm or something, but since i'm usually up till about now I wait up a little longer just to see. every day its going today, every week its going this week. I do not understand, tell me how a package can miss 6 pickups (2 a day since monday)? how does that happen?
certainly, I will not repeat this massacre You can buy the DPS-500, which is available only when I say ready