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## SST01

Started by junie, November 27, 2012, 07:53:51 PM

0 Members and 2 Guests are viewing this topic.

#### junie

heaveno Pers,

Good evening.
I finished the softstart and everything's fine but R6, R7, R8 and R9 are getting hot.
C1 is .22uF and C2 is .47uF.
My input Voltage is 240VAC, quite high i think.
Kindly let me know how to make those 4 resistor to cool down.

Thanks,
Junie

#### peranders

You could remove the 0.22 uF cap and see if it works good.
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

#### junie

Hi Pers,

Ok, i did removed the .22uf but those resistors are still getting hot and now the LED is very dim.

Junie

#### peranders

#3
Could you carefully measure the voltage (AC) over all four resistors? Just wondering, how hot are they (don't touch!)?
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

#### junie

Hi Pers,

I will measure the voltage drop of the resistors when i get home.
I touched  those resistors after I unplugged from wall socket, I cannot keep my fingers as they're hot.
Please tell me, increase C1 and C2 for lower voltage and decrease for high input voltage am i right?

Junie

#### junie

Additionally the delay time is too short I reckon, can i put 2.2 uF instead of 1uF in the timing circuit? and is it ok to use an Electrolytic capacitor?

#### junie

#6
Hi Pers,

Voltage drop is 4VAC each resistor with C1 & C2= 0.47uF
Voltage drop is 5.81AC each resistor with C1 % C2= 0.22uF

junie

#### peranders

Quote from: junie on November 28, 2012, 12:10:57 PM
Additionally the delay time is too short I reckon, can i put 2.2 uF instead of 1uF in the timing circuit? and is it ok to use an Electrolytic capacitor?
You have room for 3 pcs. 1 uF but 2u2 will work of course. Avoid electrolytics due to leakage currents.
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

#### peranders

Quote from: junie on November 28, 2012, 03:13:19 PM
Hi Pers,

Voltage drop is 4VAC each resistor with C1 & C2= 0.47uF
Voltage drop is 5.81AC each resistor with C1 % C2= 0.22uF

junie
Do you really have 4 x 120 ohms?
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

#### junie

heaveno Pers,

Yes, it's 120 ohms.

But I did installed only one cap (in C1 and C2) the value of 2.2uF, and no more heating at all.

BR,
Junie

#### peranders

#10
Sorry, will the 4 x 120 ohm not get hot if the C1 and C2 is 2.2 uF?
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

#### junie

#11
yes, Not getting hot if .22 uF only.

Sorry, it's a typo errror. the C1 and C2 is only .22uF.

#### peranders

OK, good then.
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff