bootstrapsCCS+T-TMC

[dadod]

Originally Posted by vac231

Hi Dado,

A. About other capacitors not electrolytics. Is the quality not significative for some of them (like the green C4) for example ?

B. I see the central thermal aluminium you use to cold Q94 and Q95 :

B1. Is this main dissipator DIY or available somewhere ?

B2. You have added an additional piece of metal to it.. Are Q94 and Q95 so hot ?


Have a nice day!

Nicola

A. C13 and C22 are mica, C23 is ceramic COG/NPO, and all others non electrolytic are polypropylene film/foil type.
B. Heathsink for Q94, Q95 I made from alu breaket 10x40mm 2mm thickness and main alu breaket used for output transistor is 30x50mm 3mm thickness.
B1. I did not find suitable heathsink here in Croatia and I like to make all what is possible by myself.
B2. Yes it is quite hot 50 degree C max and I made this heathsink longer(90mm) on last PCB layout because of that.
here is new corrected bill of materials.
cheers, dado

[vac231]

Good morning, Dado!

For amp :

Can I replace C2 mica with polystyrene ?


For power supply :

a. How many VA should I count for the transformer ?

b. Is C1 capacitor X2 type ?

c. Long life 50V type for C2 & C3, and low ESR for other C4-C9 ?

d. Is voltage for C4-C9 50V too ?

e. For R1, R4, R5, which power handling ?

f. For C10 & C11 the best I can find, like paper oil or MKP ?


Nicola

[dadod]

Originally Posted by vac231

Good morning, Dado!

For amp :

Can I replace C2 mica with polystyrene ?


For power supply :

a. How many VA should I count for the transformer ?

b. Is C1 capacitor X2 type ?

c. Long life 50V type for C2 & C3, and low ESR for other C4-C9 ?

d. Is voltage for C4-C9 50V too ?

e. For R1, R4, R5, which power handling ?

f. For C10 & C11 the best I can find, like paper oil or MKP ?


Nicola

For amp :

Can I replace C2 mica with polystyrene ?
Yes, even for C13 and C22 you can use polystirene if you can find as that is best type of all.


For power supply :

a. How many VA should I count for the transformer ?
I used 400VA for stereo. For dual mono 2x250VA or 2x300VA will be good.
There is no to much in transformers power.

b. Is C1 capacitor X2 type ?
No need, this is low voltage side of transformer. If you use a capacitor connected to 240V side, as one connected parallel to power switch then use X2 type.

c. Long life 50V type for C2 & C3, and low ESR for other C4-C9 ?
OK

d. Is voltage for C4-C9 50V too ?
Better use 63V for C2 and C3 and for the rest 50V is OK.

e. For R1, R4, R5, which power handling ?

f. For C10 & C11 the best I can find, like paper oil or MKP ?
MKP is OK, no need to pay stiff price for paper in oil, but you can use it off cource.

dado

[dadod]

Here is Power Supply PCB to be used for hot iron and laser printer method
dado

[vac231]

For amp:

Could you please verify where I set the returns (ground) points for speaker output and input cable (see photo below) ?

For power supply:

Which type for C1 ?

What effect for C1 and R1 ? Are they mandatory ?

I'll use 0.25W for all resistors, but 5W for R2 & R3, OK ?

[dadod]

Originally Posted by vac231

For amp:

Could you please verify where I set the returns (ground) points for speaker output and input cable (see photo below) ?

For power supply:

Which type for C1 ?

What effect for C1 and R1 ? Are they mandatory ?

I'll use 0.25W for all resistors, but 5W for R2 & R3, OK ?

C1 and R1 are not mandatory, they help to tame rectifiers noise, any tipe for C1 is OK(polyester).
Yes R2 and R3 are only 5W resistors here.
Regarding the ground connection I will prepare a block diagram of it asap. This is quite important to avoid ground loop and prevent the buzz from 50Hz to enter the amp.
Do you need gerber files for PCBs?
dado

[dadod]

Here is the block diagram of the power supply and amplifier connection.
The GND on the amp is main ground or zero V. The gnd is input ground connected internaly to the main ground via 10 ohm resistor.
dado

[vac231]

I finished to check layout components with BOM and schema. All is OK. I just noticed R25 is there, but not marked as R25 in both schema and layout. That's all...

About ground loops, I experimented them in my current system when building JLH 80W... I'm very attentive to this chapter and your own experience! I'm reading deeper your block diagram this evening.

Yes, it would be very good to have gerber files to produce the PCBs.

Nicola

[dadod]

I see that R25 is on schema and layout, just interchange Q10 and Q97 on layout.
dado

[dadod]

Just a word of warning, I never used gerber files to order PCB. I do my PCB in DIY way.