Hi DVV . My son also . He has just past a qualification that many use for CSI work . No work yet . I suggested he apply to a brewery he visited . They showed how they maintain yeasts to have a defined taste . He especailly wants to do lab work .
Sid Smith used 317 in the Marantz amps at circa 400 V . One simple way to do it if the load is constant is use 317 as a CCS . If an input resistor is used it can be zener protected for surges ( 37 V zener ? out to in ) .That also substitutes the usual 1N4007 or whatever as a reverse diode . This design is similar . Talking to Sid I suspect he did it first . The 317 has the dynamic range to deal with the typical HT ripple . Speed is OK for a class A amp .
DIY Test Equipment for Audio and Ham Radio Enthusiasts
One thing I did do recently was use a 317 as a constant voltage source out and as a constant current source in . It cheaply solved interfacing a NE 555 timer with a set of relays . No level shifter required using a voltage source which is between 21 and 40 V DC . 12 V relays above and below . A transistor and zener would do equally well ( the emitter as constant voltage source , collector as CCS ) . The advantage being the 317 is as cheap and will always give the same result .
Sid Smith used 317 in the Marantz amps at circa 400 V . One simple way to do it if the load is constant is use 317 as a CCS . If an input resistor is used it can be zener protected for surges ( 37 V zener ? out to in ) .That also substitutes the usual 1N4007 or whatever as a reverse diode . This design is similar . Talking to Sid I suspect he did it first . The 317 has the dynamic range to deal with the typical HT ripple . Speed is OK for a class A amp .
DIY Test Equipment for Audio and Ham Radio Enthusiasts
One thing I did do recently was use a 317 as a constant voltage source out and as a constant current source in . It cheaply solved interfacing a NE 555 timer with a set of relays . No level shifter required using a voltage source which is between 21 and 40 V DC . 12 V relays above and below . A transistor and zener would do equally well ( the emitter as constant voltage source , collector as CCS ) . The advantage being the 317 is as cheap and will always give the same result .
@AndrewT
Andrew, I wanted higher voltage than nominal; lower is always easier to obtain. Specifically, I want to be able to use it for voltages 55...65V, obviously fully regulated, for the power amp input stage and VAS, specifically.
@Nigel
Attaboy Nige, the supplied schematic obviously shows that the ground lift by zener trick still works. Thanks.
Andrew, I wanted higher voltage than nominal; lower is always easier to obtain. Specifically, I want to be able to use it for voltages 55...65V, obviously fully regulated, for the power amp input stage and VAS, specifically.
@Nigel
Attaboy Nige, the supplied schematic obviously shows that the ground lift by zener trick still works. Thanks.
I have built discrete component regulators for power amp output stages but never high voltage ones using LM317 etc.
That said I remember an article for an Ultra Low Distortion Amplifier in the Australian Silicon Chip magazine around 10 or more years ago - that had regulated s.s.stages.
It is not completely out-moded as Altronics still offer offer a full kitset including metalwork for this 100 watt per channel project.
Unfortunately I ditched the issues inwhich this featured - I had no interest in outlaying the capital to buy one.
From memory it used LM317 's in each of the supply rails in combination with an NPN device. I do not remember why they did not use a LM337 in the negative rail.
I think there was a network of zener diodes in parallel with the LM317 and NPN combo to ensure that the voltage presented at switch on did not exceed a safe level.
I thought this worth mentioning as a risk to be avoided.
Anybody in Australia still have these articles?
Michael J.
That is a nice performance of the Rimsky-Korsakov I think.Brad, thanks for the link, very nice!
I blame the late Orthodox Easter for the cold weather we're having. It should not be this cold on May 5th! Now that both Easters and Passover are out of the way, the weather can warm up.
More than a month between the two Easters is unusual.
Around here, even more strangely, many are celebrating Cinco de Mayo. Some look at me oddly (well, even more oddly than usual) when I wish them a happy day for that, supposing that I don't have a clue as to the history behind it (wrong!). Mutterings of Gringo loco...
We just had two days of near-record heat, high winds, low humdity, and naturally, fires. Fortunately they had anticipated the latter, and residents in affected areas had been dutiful about keeping cleared perimeters. Now the weather has returned to more typically overcast and gloomy, which suits me just fine.
Quite so - we had the Orthodox Christian New Year between Jan, 13 and 14, at midnight. Fireworks and all.
This works wonderfully for us - we get to celebrate the usual Christmas and New Year, PLUS the Orthodox version.
I am thinking of writing to my MP to suggest we also celebrate the Chinese New Year, which is around January 21, I am told. They are, after all, considered to be a friendly nation here.
On a personal note, I might start celebrating the Thai New Year, as I have wonderful memories of my visit to Thailand in June 1992. I have never encountered a more polite people than the Thai, we all have much to learn from them.
Brad, thanks for the link, very nice!
I blame the late Orthodox Easter for the cold weather we're having. It should not be this cold on May 5th! Now that both Easters and Passover are out of the way, the weather can warm up.
More than a month between the two Easters is unusual.
Surely you jest, Sir Knight?
Cold? We have 32 deg. C (app 90 deg. F) for days over here, I donned my shorts on, like 90% of the population a week ago.
And, God bless the female population, tight shorts and tighter vests provide for impressive, er, progressive pronounced traits of the female population. A sight for sore eyes.
My air con has not been switched off a good week.
You know, we have all but lost spring and automn here, we seem to jump from winter to summer in like two weeks. Same thing later on, we jump from summer to winter in like 3 weeks.
And the snow in winters is more or less gone, and when there is some, it's not the sedate slow snowing from my childhood, it's an angry snowstorm.
And the snow in winters is more or less gone, and when there is some, it's not the sedate slow snowing from my childhood, it's an angry snowstorm.
Sounds like you're becoming like Australia, we're notorious for having dramatic jumps in climatic conditions, but it's always been that way! Melbourne is known as the city where you can have 4 seasons in one day ...
It's a good thing we have those sceptics around, telling us that there's no such thing as climate change - otherwise we might need to worry a bit, !
It's a good thing we have those sceptics around, telling us that there's no such thing as climate change - otherwise we might need to worry a bit,
!
Sounds like you're becoming like Australia, we're notorious for having dramatic jumps in climatic conditions, but it's always been that way! Melbourne is known as the city where you can have 4 seasons in one day ...
It's a good thing we have those sceptics around, telling us that there's no such thing as climate change - otherwise we might need to worry a bit,
Like the ones touting global warming ....
Kinda like worrying about THD and what we can do about it ..
I'm sure when the Pharaohs looked out on to their fertile land and beautiful lush gardens , they thought ..!!!
Global warming ...nah ....
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