[NEW] SoftStart+Push Button V1.0

[robydream]

Hi everyone. I have designed a softstart with push button so that the amplifier can be switch ON or OFF upon pressing push button.

Delay is 114ms and would like to show schematic if this will work and how many time it needs soft start to be connected to thermistors? I read online that the recommanded time is 100ms.

So what do you think of schematic? Do i need some modifications?

Here is the schematic🙂

 

[robydream]

Here i publish UPDATED SoftStart that have delay 1,5sec. That is more that enought (1 cycle = 50Hz/230VAC = 217ms, @50Hz we have 5 cycle to limit inrush current so 5 cycles x 217ms = 1086ms or 1,1second is needed so 1,5sec is set using R6 - 68k and C6 - 22uF to give 1,5sec delay)-

Here is schematic and PCB files who wants it to build it.

 

[alex mm]

PCB rev.2

And another PCB with schematic changed a bit .🙂
Regards,
Alex

 

[robydream]

Streamable - free video publishing

 

[adzqia79]

very good softstart design 🙂

 

[ingo50]

Hallo robydream-
Your layout has no fuse for the standby-trafo!!
The layout from alex-mm has got it. very good . Mybee reduce the fusesize to ca. 80mA or so.
always stay on the safe side of life

Ingo

 

[robydream]

Thanks for comments...i designed schematic and PCB design was from viktor_1986 that have done very nice design (V1.0)...and PCB designer for (V2.0) was alex_mm know for master of design of PCB...version 2.0 is much better that 1.0 because it have AUX 12VDC for speaker protection, fan control etc...

thanks Ingo50...i put wire with fuse before trafo on my amplifier case so it have small fuse around 100mA before mains go to master trafo....also please note that R3 is veryx important for soft switch it depends on used mosfet IRF3205 use first R3 1k and slow increase to 10k when switch will be working...it is very usefull softstart and it cost me around 15€ with PCB and all components...sure it can be easy build like elektor softstart with large capacitors for relay but it it for me not safe because it uses X2 capacitor for mains not the transformer...