Klipsch Bash SMPS DIY Rebuild

[crazifunguy]

Why not start one more project
I have a very nice Klipsch Subwoofer that has failed due to poor design in the power supply. Origionally I was going to try and replace just the transformer but after fooling around with it I decided to reverse engineer and redo the whole power supply. Origionally the SMPS used what I believe to be an EER/ER35 Transformer with a vertical bobbin. I have found a good source of ETD supplies at mouser.com so I am planning on re-creating this using one of these cores. I understand that this is not going to be an easy task so I am just starting with the basics of creating the schematic and pcb's.

From what I gather BASH uses self-oscillating push-pull supplies in most of thier amps. Basically any BASH SMPS with a PDC board uses this mode of operation. I have 2 seperate amps/power supplies and they both use the same PDC control board. From this I believe that the ratio of the windings in the transformer are main operational factor.

I will do my best to make sure the schematics and pcb's are accurate as well as component values.
More to come!!!

[crazifunguy]

I started with the PDC board 660038RA.


***ALL RESISTORS ARE 1%***
R1 - 200K
R2 - 1K
R3 - 392
R4 - 750
R5 - 750
R6 - 392
R7 - 750
R8 - 750
R9 - 200K
R10 - 200K
(4/5) (7/8) (9/10) are in parallel to obtain desired values.


C1 - R1C 472 KCS 605 (4700pF 60V 5% ????? )
C2 - 3300pF 5% 100V
C3 - 3300pF 5% 100V

D1 - 1N3070
D2 - 1N3070
D3 - 1N5245B
D4 - 1N5245B
D5 - 1N4148
D6 - DIAC (UNKNOWN VALUE)

Q1 - MPS A92

[crazifunguy]

I am working on the schematic of the SMPS. Tracing circuits and looking up values is not much fun. I have come to the inductors and I cannot find any data.

How can the inductance of a common mode choke be measured with a LRC meter?

If I measure both sides seperatley I get a value of 8.5mH. Is this an acceptable way to measure this?
That value seems rather large for the common mode choke in the EMI filter.

[MicrosiM]

I am working on the schematic of the SMPS. Tracing circuits and looking up values is not much fun. I have come to the inductors and I cannot find any data.

How can the inductance of a common mode choke be measured with a LRC meter?

If I measure both sides seperatley I get a value of 8.5mH. Is this an acceptable way to measure this?
That value seems rather large for the common mode choke in the EMI filter.

very good job indeed, EMI chock's?

If they are EMI chock's, its normal to get 8.5MH a picture will help more

[crazifunguy]

I'll post some pictures right after this.
I finished my first version of the input side of the SMPS. Please have a look and provide feedback. Some of the larger traces could be converted to pours but it should not have an effect on performance to my knowledge.


The origional SMPS had selectable voltage 120/230. Since I live in the US I am only making a 120V version. The only difference I could find is that the jumpers place the caps and resistors in series vs parallel. This also allowed for extra space and ease of routing the traces. I was also able to add 2 large heatsinks for each FET.

[crazifunguy]

Origional SMPS


SMPS - PDC - COMMON MODE CHOKE


LCR Reading of one side of choke

[crazifunguy]

I have done some searching and reading. I still cannot find if I am measureing the common mode filter properly. I might purchase one with a known value and compare measurements. I also did some component searching. Murara has very similar components in the same footprint but at 2A only 1.5mH

[crazifunguy]

I have still been working on the PCB moving some things around. I still have alot of schematic work to complete.....More to come soon when I have the time to tinker!!

[crazifunguy]

I have finished my first version of the custom PCB please review and inform.

[TamasM]

Hi Crazifunguy,

I have a Klipsch RW12d and the power supply went wrong also. I found a lot's of information in your blog. Many thanks for that!
The PS PCB is different but the PDC board in my power supply. I had to draw down the whole PS to understand where is the problem. (If somebody needs, just send me a mail)
The DIAC type on the 660038RA board is DB6. It is very rare by the way in Hungary...

TamasM