If you pull the relay coil voltage off the main power supply filter caps and trigger it to engage when they charge to say 50 or 60% it will provide you a longer delay and soften the start even more. Great project and love the PCB layout design.
Hi, thanks for the time making the video. Have you a moment to offer some guidance? I've been looking for a soft start circuit to use on a Peavey Pro Audio amp - class D, 240V/10A mains. It lost its soft start when the daughter board that does standby/power on died. I can't get a replacement board and their design with 20 odd surface mount LED's is a PITA so I have just removed it in full. That daughter board used to, at power on, close a relay on the main Amp board that activates the amplifier. I currently close that using a relay from a 12V trigger. I would like to add soft start again and am hoping to use an "off the shelf" option as it's been years since I worked designing such circuitry. Are you happy with this or some of the ebay options you may have seen (many seem based on thermistors providing the initial current until the relay shorts them)? This one seems a little bulkier having the ceramic resistors I guess but they are considered more reliable I think? May I enquire of you the parts you ended up selecting from Jaycar? That's where I'll be grabbing mine if I follow your steps on this :) I'm in Brisbane by the way. If you have an interest in custom enclosures for any of your small creations let me know as I can 3D print them. Ohh... Dim bulb is a good setup - nicely done!
I believe rod's article talked about using thermistors, and I've seen this all over ebay. They work and are more compact (probably with a safer way to power it, too.).
I'm a big fan of a soft start on the valve amps I build, I usually add a CL-80 thermistor in the load (hot) line and it prevents spikes and allows for a smooth start. What is the advantage of this circuit ?
Dealing with the large inrush current of power transformers above 300VA (500VA, etc.). The initial peak current can be well over 15A which will pop your circuit breakers.
Why didn't you use the secondary voltage for the soft start circuit, instead of using the primary and creating a specific RC timed circuit that isn't really universal for different projects? Just curious. Switch the primary of the circuit, based off of the secondary voltage rising to a certain level.
what wattage is the Zener diode you used and where would you suggest putting a ground wire cause I plan on using this design on my st-3000Va step up step down power inverter and what wattage is the 470 ohm resistors
@@AstrosElectronicsLab not to bother you again but just a question about the relay are you using all 5 pins in the circuit or just 4 of them so I get it right
If you pull the relay coil voltage off the main power supply filter caps and trigger it to engage when they charge to say 50 or 60% it will provide you a longer delay and soften the start even more. Great project and love the PCB layout design.
Yes, that indeed is another way to do it. Xraytonyb had a similar circuit.
Hi, thanks for the time making the video.
Have you a moment to offer some guidance?
I've been looking for a soft start circuit to use on a Peavey Pro Audio amp - class D, 240V/10A mains. It lost its soft start when the daughter board that does standby/power on died. I can't get a replacement board and their design with 20 odd surface mount LED's is a PITA so I have just removed it in full.
That daughter board used to, at power on, close a relay on the main Amp board that activates the amplifier. I currently close that using a relay from a 12V trigger.
I would like to add soft start again and am hoping to use an "off the shelf" option as it's been years since I worked designing such circuitry.
Are you happy with this or some of the ebay options you may have seen (many seem based on thermistors providing the initial current until the relay shorts them)?
This one seems a little bulkier having the ceramic resistors I guess but they are considered more reliable I think?
May I enquire of you the parts you ended up selecting from Jaycar? That's where I'll be grabbing mine if I follow your steps on this :)
I'm in Brisbane by the way. If you have an interest in custom enclosures for any of your small creations let me know as I can 3D print them.
Ohh... Dim bulb is a good setup - nicely done!
I believe rod's article talked about using thermistors, and I've seen this all over ebay. They work and are more compact (probably with a safer way to power it, too.).
As for parts, I used jaycars 24v Panasonic relay.
I'm a big fan of a soft start on the valve amps I build, I usually add a CL-80 thermistor in the load (hot) line and it prevents spikes and allows for a smooth start. What is the advantage of this circuit ?
Dealing with the large inrush current of power transformers above 300VA (500VA, etc.). The initial peak current can be well over 15A which will pop your circuit breakers.
Why didn't you use the secondary voltage for the soft start circuit, instead of using the primary and creating a specific RC timed circuit that isn't really universal for different projects? Just curious.
Switch the primary of the circuit, based off of the secondary voltage rising to a certain level.
what wattage is the Zener diode you used and where would you suggest putting a ground wire cause I plan on using this design on my st-3000Va step up step down power inverter and what wattage is the 470 ohm resistors
1W. It only powers the relay. 0.5W for 470 ohms.
what about the ground wire idea I asked about
@reneeandcurtisarcand not sure what you mean about ground. This circuit is floating of ground/earth
@@AstrosElectronicsLab that makes sense
@@AstrosElectronicsLab not to bother you again but just a question about the relay are you using all 5 pins in the circuit or just 4 of them so I get it right
7:03 Unibrow moment!