Dynaco C-100 Energy Storage System (Capacitor Bank)

[oldphaser]

I thought there might be some interest by some of you folks out there in building your own capacitor bank.
So I thought I would start off by posting what I could find on the Dynaco C-100.

NOTE: Perhaps we can get Joe's comments on the attached schematic diagram.




Here are some miscellaneous comments:


Dynaco C-100 Energy Storage System
Designed by Wade D. Burns(?), chief engineer. It appears that he may still be alive and living in Blackwood, N.J..

Apparently the C-100's may also be stacked in multiples. They were sold "assembled only".

There may even be an article on the C-100 in an old Audio Amateur magazine. (circa 1976?) perhaps written by Walt Jung?

[FONT=&amp]The jack on the ST400/ST416 is an RWK-4-31SL, the mating cable connector on the C100 is an RWK-4-24C-3/8

[/FONT]There is some discussion on http://www.updatemydynaco.com/Stereo400.html

C-100 Capacitor Bank
Large filter caps in the power supply hold up the power supply rails even when the going gets rough. The Stereo 400 and 416 were there at the birth of the "Super Amps" and the start of the microfarad wars. Manufacturers started throwing 10's of thousands of microfarads into their power supplies, all in the name of better bass. The C-100 capacitor bank was the ultimate answer to the microfarad wars. You could add a C-100 to a Stereo 400 or a 416.
The schematic shown below contains revisions and corrections pointed out to me by Jim Switzer in an email on 12/17/2016. I added a few more annotations that make the schematic a bit easier to analyze and understand. In the course of that, I've written a circuit description that contains a mystery, so the schematic might still have an error.

http://www.updatemydynaco.com/documents/C100CircuitDescription.pdf

There is currently (1) C-100 listed on ebay:
http://www.ebay.com/itm/VINTAGE-DYNACO-C-100-ENERGY-STORAGE-UNIT-/272614474386?hash=item3f7916c292

Ed

 

[grapplesaw]

Ed I am impressed with your write up. I am afraid I need to question the need of such complex system. We are building large power supplies at this time for the monster mono builds. Perry has a good build with a soft start setup to avoid high load on start up but left with petted to metal from there on. I am working on a dual triode transformer connected to four 22,000 caps. This will be interesting thread to follow to see everyones thoughts.

If I understand this right the system will kick into slow charging rate when the mean voltage drops to low. this leaves me thinking that the supply may not preform well at high current needs with various charge rates.

 

[oldphaser]

Glen,

The thought here was that something like the C-100 would inter-connect via a connector to an existing transformer and power supply caps on a Phase Linear 400 or 700 much like Dynaco did with the 400/416 series of amplifiers. Not creating a new power supply from scratch with a new transformer or a new amplifier design. I would like to see more about Perry's soft start circuit. If it is already posted, please point me there.

Thanks!
Ed

 

[grapplesaw]

Thanks Ed. That makes it clear as I missed that concept. Now I will look at the schematic closer and see how to adjust for different rail voltage. Do you see much heat from the 600 ohm 10 watt transistors? I assume they are only in circuit at lower voltages and come out as full charge is reached.




Here is one tread on Perry's power supply

http://forums.phxaudiotape.com/showthread.php/7772-Mono-Amp-Powers-Supply-s

 

[WOPL Sniffer]

I was kinda wondering how the contacts on the relays held up with the large current kick....

Very cool piece though. Thanks Ed



As for the "Soft Start's" I am experimenting with, I think I got my 20 bucks worth. They seem to be the ticket (I.e. no brown outs during the charging of the 6 bulk caps). They also came with the transistors to turn off the circuit in case of a heat problem. They seem to be adjustable but the board didn't come with any directions so I gotta play.... The first power supply is about finished and between taxes and the Honey DO NOW list, I'll be back in the shop working Monday... Yee-haaaaa...

 

[oldphaser]

Does anyone out there have a copy of The Absolute Sound Vol. 3 Number 9 Spring 1977 "The Double Dyna" starting on page 28......
Dynaco Double 400 modified by Frank Van Alstine.

It may also contain some interesting information on the subject of a beefed up power supply.

Apparently Dynaco copied some of Frank's work and implemented it in the Dynaco 416 and C-100?????

Ed

 

[Bradrock]

I happened across this set. I search Dynaco a lot & have never seen the c-100 for sale before. This would be fun to play with. Christmas is soon!


https://www.ebay.com/itm/DYNACO-STE...576244?hash=item3d4ee417f4:g:ongAAOSwdjdaB6Oa

 

[WOPL Sniffer]

Ed, why would you advertise this guys address and email here? If somebody just threw my shit out there for every BOT and Somali pirate to see I'd have to hunt them down and sock them in the neck.... please take it down.

 

[WOPL Sniffer]

Just put his Social Security Number here...... can't do much with that right?

 

[WOPL Sniffer]

Shouldn't have been done per MY request. It was the right thing to do. but thanks

 

[wattsabundant]

Does anyone out there have a copy of The Absolute Sound Vol. 3 Number 9 Spring 1977 "The Double Dyna" starting on page 28......
Dynaco Double 400 modified by Frank Van Alstine.

It may also contain some interesting information on the subject of a beefed up power supply.

Apparently Dynaco copied some of Frank's work and implemented it in the Dynaco 416 and C-100?????

Ed

I don't know if Frank is still around, but I'm quite sure Dynaco didn't copy Frank. I visited Frank at his home/office outside Minneapolis a little over 30 years ago. What Frank did was modify Dynaco gear. I recall a modified PAT 5 preamp.

I'll likely see John Peterson of Sound Values/Sound Valves (yes he's still around) this week and get the scoop on the C100 (he had one).

 

[laatsch55]

That's cool Don!!!!

 

[wattsabundant]

As for the "Soft Start's" I am experimenting with, I think I got my 20 bucks worth...

Gotta be careful with softstarts that limit the inrush with resistors and amps without an output relay. It's a catch 22. At turn on the DC voltage starts to walk up. The front end differential amp isn't stable yet. This results in some DC on the output that goes into the speaker, but probably not enough to hurt the speaker. This loads down the power supply and hence the softstart and it sits there. Meanwhile the current limiting resistors are getting hot. If there is an output relay then it's no problem because the relay doesn't pull in until the amp is stable.

My preference for a softstart is a phase angle controller. Here's one on EBAY. Phase angle controllers don't use current resistors, instead they use a triac to walk up the voltage. the down side is phase angle controllers cost a lot more.

https://www.ebay.com/itm/HDR-Ametek-PF1-480-40-TX-01-40A-90-480VAC-4-20mA-SCR-Phase-Angle-Power-Control/282865836548?hash=item41dc1e2204:g:EEIAAOSwLVZV3kFS.

 

[grapplesaw]

Gotta be careful with softstarts that limit the inrush with resistors and amps without an output relay. It's a catch 22. At turn on the DC voltage starts to walk up. The front end differential amp isn't stable yet. This results in some DC on the output that goes into the speaker, but probably not enough to hurt the speaker. This loads down the power supply and hence the softstart and it sits there. Meanwhile the current limiting resistors are getting hot. If there is an output relay then it's no problem because the relay doesn't pull in until the amp is stable.

My preference for a softstart is a phase angle controller. Here's one on EBAY. Phase angle controllers don't use current resistors, instead they use a triac to walk up the voltage. the down side is phase angle controllers cost a lot more.

https://www.ebay.com/itm/HDR-Ametek-PF1-480-40-TX-01-40A-90-480VAC-4-20mA-SCR-Phase-Angle-Power-Control/282865836548?hash=item41dc1e2204:g:EEIAAOSwLVZV3kFS.

Thanks Don for this. The timing of your post is in line with my upcoming dual 600 amp build to which I am collecting parts.

I just ordered three soft start controllers for $17 each of the type that use resistors earlier today. Wish I had this info then. I will be ok with these I hope.

The question now remains is my amp design . I will have a DCP/ delay on output relay system of either a modified Watts Abundant unit or a stock dual 500 setup run by the front PL Dual500 meter board relay setup. . I have two 1000watt triodal transformers which will net 120 - 0 - 120 dc after the bridge rectifiers. I need to use two to get enough power to supply this rail voltage in Stereo for 600 Watts each channnnel with a little head rooom.

Option A is that I will use two toroidal transformers who’s outputs connect to seperate bridge rectifiers the join to icommon main caps after being rectified. Both transformers mains supply to come from one soft start unit. Perry has tested this so it does work. This is easiest to do.

Option B is the same except each transformers has its own soft start relay( basicly two units the same). This redundant soft start may cause additional problem although I think not but will lighten the load o he resistors inside. .

Option C is to run each channel with one transformer and seperate main capacitors. Resulting in two mono amps in a single chassis. This is a more complicated set up because of redundant systems for DCP and possible need to split the control board into two with indepenat power supplies. No cross talk with this design.


Option C would be my choice if I can run a standard configured control board using power supplied from only one channel power caps. The DCP board in standard configuration should be ok to Handel both mono amp outputs I think. Don you probably have some thoughts on this.

 

[THD+N]

Glen,
I have a pair of Krell KSA50 clones that I built. The power supply per mono amp consists of 4 20kuF caps (2 20kuF per rail, paralleled). For current in-rush, I am using a CL-60 NTC limiter (per amp).

Because of the Krell design (dual diff front-end), there is no turn on thump or noise. However, the in-rush limit happens so fast, you may not have any thump/pop depending on the amp design. Since your going to use a DCP anyway, you may want to explore this option. It is inexpensive and it works great.


The only draw back is that if there is a quick power interruption (the standard lights go out for a moment, then come back on), the NTC will not provide in-rush limit until it cools back down to room temp. In use, the NTC gets pretty warm, but it is supposed to.

I've never had any issues. There are various NTC's to choose from depending on current requirements.

 

[wattsabundant]

Thanks Don for this. The timing of your post is in line with my upcoming dual 600 amp build to which I am collecting parts.

I just ordered three soft start controllers for $17 each of the type that use resistors earlier today. Wish I had this info then. I will be ok with these I hope.

The question now remains is my amp design . I will have a DCP/ delay on output relay system of either a modified Watts Abundant unit or a stock dual 500 setup run by the front PL Dual500 meter board relay setup. . I have two 1000watt triodal transformers which will net 120 - 0 - 120 dc after the bridge rectifiers. I need to use two to get enough power to supply this rail voltage in Stereo for 600 Watts each channnnel with a little head rooom.

Option A is that I will use two toroidal transformers who’s outputs connect to seperate bridge rectifiers the join to icommon main caps after being rectified. Both transformers mains supply to come from one soft start unit. Perry has tested this so it does work. This is easiest to do.

Option B is the same except each transformers has its own soft start relay( basicly two units the same). This redundant soft start may cause additional problem although I think not but will lighten the load o he resistors inside. .

Option C is to run each channel with one transformer and seperate main capacitors. Resulting in two mono amps in a single chassis. This is a more complicated set up because of redundant systems for DCP and possible need to split the control board into two with indepenat power supplies. No cross talk with this design.


Option C would be my choice if I can run a standard configured control board using power supplied from only one channel power caps. The DCP board in standard configuration should be ok to Handel both mono amp outputs I think. Don you probably have some thoughts on this.

The 700 relay board is rated for 100VDC with 2 x48VDC relays in series. I'm not sure how well the coils will hold up with 60VDC across them. Capacitor C3 would need to be rated for 10uf/160VDC. Here is a Mouser P/N for the cap. https://www.mouser.com/ProductDetail/Nichicon/UVR2C100MPD1TD?qs=sGAEpiMZZMtZ1n0r9vR22Xsgo43SDd6qLAvOsivl9WA%3d

 

[wattsabundant]

Here's another thought. Does the softstart circuit use a relay contact to short out the current limiting resistor once the caps are charged?

 

[grapplesaw]

The 700 relay board is rated for 100VDC with 2 x48VDC relays in series. I'm not sure how well the coils will hold up with 60VDC across them. Capacitor C3 would need to be rated for 10uf/160VDC. Here is a Mouser P/N for the cap. https://www.mouser.com/ProductDetail/Nichicon/UVR2C100MPD1TD?qs=sGAEpiMZZMtZ1n0r9vR22Xsgo43SDd6qLAvOsivl9WA%3d

Thanks Don
I was thinking to adjust the voltage with resistors on the DCP board to reduce the the correct Voltage
As an option I can use the stock DCP in the Dual 500 meter board. I will post both layouts later.

 

[grapplesaw]

Here's another thought. Does the softstart circuit use a relay contact to short out the current limiting resistor once the caps are charged?

Hi Don
here is what I have so far on the softstart layout

 

[wattsabundant]

Hi Don
hete is what I have so far on the softstart layout

The cut sheet and the picture indicates a 220V circuit. Is that what you bought?

I attached a cut sheet for a phase angle controller chip I've used before. When used with modern triacs there is no switching noise and no snubber needed. The drawing shows an electrolytic cap CS with the wrong polarity. Builder beware.

PLmavenman has a stalled project to use a microcontroller softstart.

View attachment TDA1185.pdf