Crescendo Me Protection
Bonjour everyone,
I am coming in this thread, because i saw earlier in this post (2 years ago) you had referred to the Crescendo Me Protection, i did not find any other post about it.
http://www.diyaudio.com/forums/soli...ting-ideas-1970s-ips-ops-115.html#post4825705
I build this amp of Elektor 2001 Magazine, i drew the PCB with all-in one ( Amp and protection) my V0.1 (first test PCB) have very good result.
I have couple of questions about.
Am i in the right Thread or do i have to creat a new one.
Thanks
FR
Bonjour everyone,
I am coming in this thread, because i saw earlier in this post (2 years ago) you had referred to the Crescendo Me Protection, i did not find any other post about it.
http://www.diyaudio.com/forums/soli...ting-ideas-1970s-ips-ops-115.html#post4825705
I build this amp of Elektor 2001 Magazine, i drew the PCB with all-in one ( Amp and protection) my V0.1 (first test PCB) have very good result.
I have couple of questions about.
Am i in the right Thread or do i have to creat a new one.
Thanks
FR
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Bonjour everyone,
I am coming in this thread, because i saw earlier in this post (2 years ago) you had referred to the Crescendo Me Protection, i did not find any other post about it.
http://www.diyaudio.com/forums/soli...ting-ideas-1970s-ips-ops-115.html#post4825705
I build this amp of Elektor 2001 Magazine, i drawed the PCB with all-in one ( Amp and protection) my V0.1 (first test PCB) have very good result.
I have couple of questions about.
Am i in the right Thread or do i have to creat a new one.
Thanks
FR
Hi FR,
In fact, Crescendo Me Protection was mentioned here because Thimios used it in one of his tests. Probably he can answer some of your questions
Cheers,
Valery
Thank Valery, should i contact Thimios in PM or do i post my questions here??Hi FR,
In fact, Crescendo Me Protection was mentioned here because Thimios used it in one of his tests. Probably he can answer some of your questions
Cheers,
Valery
Cheers,
Francois
Thank Valery, should i contact Thimios in PM or do i post my questions here??
Cheers,
Francois
Hi Francois, post them here - Thimios will see them anyway.
Cheers,
Valery
Thanks Valery,
I use the crescendo Me protection, see attached.
As you see, they are 2 x 35Vac connected and 0V coming directly from the transformer.
This is Elektor 2001 article magazine:
"The protection circuitry (Figure 2),which is located on a separate
printed circuit board, includes overload protection, DC protection, a
switch-on delay for the output relay and a voltage detector that directly disables the output relay when the power is switched off or any of the transformer voltages is absent"
1- The relay did not switched on after the delay of 8Secondes, if i take off R29 the relay switched on after 8s ..
2- When i disconnected one of the 35Vac the output relay do not switched-off
Thanks for your help
Francois
I use the crescendo Me protection, see attached.
As you see, they are 2 x 35Vac connected and 0V coming directly from the transformer.
This is Elektor 2001 article magazine:
"The protection circuitry (Figure 2),which is located on a separate
printed circuit board, includes overload protection, DC protection, a
switch-on delay for the output relay and a voltage detector that directly disables the output relay when the power is switched off or any of the transformer voltages is absent"
1- The relay did not switched on after the delay of 8Secondes, if i take off R29 the relay switched on after 8s ..
2- When i disconnected one of the 35Vac the output relay do not switched-off
Thanks for your help
Francois
Attachments
Thanks Valery,
I use the crescendo Me protection, see attached.
As you see, they are 2 x 35Vac connected and 0V coming directly from the transformer.
This is Elektor 2001 article magazine:
"The protection circuitry (Figure 2),which is located on a separate
printed circuit board, includes overload protection, DC protection, a
switch-on delay for the output relay and a voltage detector that directly disables the output relay when the power is switched off or any of the transformer voltages is absent"
1- The relay did not switched on after the delay of 8Secondes, if i take off R29 the relay switched on after 8s ..
2- When i disconnected one of the 35Vac the output relay do not switched-off
Thanks for your help
Francois
Looking at the schematic, here is what I see:
1- R29 shunts the LED too much, so you can increase its value up to, say, 10K. This resistor aims to discharge C9 after the voltage reaches the level where the LED stops conducting.
2- The way those diodes are arranged (D7, D8), the speaker will get disconnected only in case both voltages go off at the same time.
Thanks Valery,
I will try with 10K.
For the second part, That's what I thought. that can not work like Elektor wrote in the article.
What do you thing that i have to change to have the relay switch-off when just one 35Vac is connected ?
Thanks, (ready for the world-cup)
Francois
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Hi Francois,
though I'm not Valery, I'll try to help you: Duplicate R31, i.e. one resistor in series with each diode D7, D8. Then inject 35 Vac to one of these diodes and decrease R29 or increase R30 until the speaker relay opens. Make sure that if you inject 35 Vac to both diodes, the relay must close again.
Best regards!
though I'm not Valery, I'll try to help you: Duplicate R31, i.e. one resistor in series with each diode D7, D8. Then inject 35 Vac to one of these diodes and decrease R29 or increase R30 until the speaker relay opens. Make sure that if you inject 35 Vac to both diodes, the relay must close again.
Best regards!
Hi Valery,please look at the schematic again
This is a working circuit,exactly as descripted in Elektor.
and a voltage detector that directly disables the output relay when the power is switched off or any of the transformer voltages is absent
Tested!
If any of the transformer A.C voltage is absent, d.c voltage at the common cathode connection D7,D8 decrease from 34v to 24v which is not enough to drive the led.
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Hi Kay, thanks for your help,
Hi Thimios, thank you, i am glad you tested it.
That is not working here, now i have 38V instead of 35V...is that the reason why that is not working ???
Francois
Yes,according to new measurments,this is a very critical circuit.
Now i wonder if it is a good circuit .
I will post measurments under normal and under fault conditions.
This fault is the absence of one a.c winding.
Picture in the right is under normal conditions.
Picture in the left is under fault.
I have tried to increase R29 to 10K but then relay stays energized even one of the a.c removed.
Using a trimmer here i ended again at 3K3 value.
Do they choose to stay at the end of conditions in order to open the relay instantly after amplifier power off?
Now Valery you have all the story
Attachments
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Hi Valery,please look at the schematic again
This is a working circuit,exactly as descripted in Elektor.
and a voltage detector that directly disables the output relay when the power is switched off or any of the transformer voltages is absent
Tested!
If any of the transformer A.C voltage is absent, d.c voltage at the common cathode connection D7,D8 decrease from 34v to 24v which is not enough to drive the led.
OK, that requires pretty fine tuning at particular voltage levels. I don't really like the designs, so heavily dependent on the supply voltage.
That means - it's possible to tune the thing up, adjusting R29 in a way that the LED will get enough voltage with both supplies working, but not enough with both supplies in place.
Sorry Valery but i can't understand what you mean.
No i don't like this circuit too.
I have see another issue,the d.c protection circuit activete under no d.c fault conditions.
When amplifier play loud (no clip) relay cut the speakers.
BTW is it posible to improve this circuit?
How this T10 control using 0,17v only?
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Sorry Valery but i can't understand what you mean.
No i don't like this circuit too.
I have see another issue,the d.c protection circuit activete under no d.c fault conditions.
When amplifier play loud (no clip) relay cut the speakers.
BTW is it posible to improve this circuit?
How this T10 control using 0,17v only?
Finally this circuit as publised connected completely to Slewmaster and function absolutely normal.
Power supply +/-50v
Playing up to hard clipping levels all are fine.
Attachments
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Thanks, Thimios and Valery,
If i understand right, the circuit function with +-50V but not with +-35V as published ?????
But is it posible to improve this circuit for +-35V,
And do you think that will change if we duplicate R31 like Kay had suggested
If i understand right, the circuit function with +-50V but not with +-35V as published ?????
But is it posible to improve this circuit for +-35V,
And do you think that will change if we duplicate R31 like Kay had suggested
Hicoco,all my test done using 2x35v a.c( transformer 2x35v).
35v a.c after rectifier-filter=1.41x35=49.35v
The same for the other coil.
That's why i say +/-50v.
BTW IC2-T10 is the power lose detector.
This circuit monitor the 2x35v a.c directly to transformer's winding.
Power supply for the rest of the circuit is the amplifier's power supply +/-50v.
In the End....this is an old schol protection circuit.
Now days hi class protection solution is the Valery-Jeff 21'' century protection.AMP CONTROL BOARDS – Virtual Zero Audio Store
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Thimios,
Thanks, i did not know this boards... i appreciate this.
For now i will love to be able to fix this all school circuit, i did the same measurement that you and when i removed one of 35 Vac wire i have 20,7 Vac the same measurement when the two 35 Vac wire are connected
Thanks, i did not know this boards... i appreciate this.
For now i will love to be able to fix this all school circuit, i did the same measurement that you and when i removed one of 35 Vac wire i have 20,7 Vac the same measurement when the two 35 Vac wire are connected
