I'm just completing a high quality double sided, silk screen PCB which contains a soft start circuit plus a power on circuit. The power on circuit enables any switch to be used (doesn't have to be mains) to power up your amp - broadens selection of switches available for front panel. The soft start simply limits the inrush current when power is applied. If anyone is interested I could make these available as just PCB or with all components.
I've got no intention to ruin your enthusiasm, but while you're at it you might check out the soft start circuits from www.lcaudio.com and, particularly, www.hypex.nl. I've just bought two of the soft starts from Hypex, one for each of my power amps, it allows both 115 and 230 V mains, LED’s for standby and power up, pushbutton or switch and a PTC «thermal fuse»/overheat protection. The only complaint I have about the Hypex thing, is that it should have a regulated AUX power supply output for other switching purposes for example (it has a small 12V 2VA transformer).
best regards
KJ
best regards
KJ
KJ42:
Thanks for the links. I prefer to build all my own stuff - so, yes I could buy ones ready made, but it's not as much fun!
My board is a little larger than the hypex, but contains essentially the same functionality - soft-start (not with triac), remote power on (ie push button or other switch), individual LEDs showing standby and power on + the ability to adjust the intensity of the LEDs - I like to be able to do this to suit the room.
The one thing I don't like about the hypex is the exposed terminals for the mains voltage. Even though they say to use insulated faston connectors, I prefer enclosed terminal blocks.
An image of the PCB layout is attached. The boards are in production now.When I have built and tested them I will be able to offer bare PCBs for anyone wishing to build their own. Likely cost around US$20 per PCB (double sided, plated through, solder mask and silkscreen)
Thanks for the links. I prefer to build all my own stuff - so, yes I could buy ones ready made, but it's not as much fun!
My board is a little larger than the hypex, but contains essentially the same functionality - soft-start (not with triac), remote power on (ie push button or other switch), individual LEDs showing standby and power on + the ability to adjust the intensity of the LEDs - I like to be able to do this to suit the room.
The one thing I don't like about the hypex is the exposed terminals for the mains voltage. Even though they say to use insulated faston connectors, I prefer enclosed terminal blocks.
An image of the PCB layout is attached. The boards are in production now.When I have built and tested them I will be able to offer bare PCBs for anyone wishing to build their own. Likely cost around US$20 per PCB (double sided, plated through, solder mask and silkscreen)
Attachments
Hi to all diyaudio folks,
This is my first post on diyaudio. Lots of great stuff.
Hello smithy666, your circuit seems great. I'm very interested in your soft-start circuit, but I need a 120 / 240 volts version.
Can you accept to send me the schematics. This way I will be able to modify and adapt it to my needs.
Thanks
AL
This is my first post on diyaudio. Lots of great stuff.
Hello smithy666, your circuit seems great. I'm very interested in your soft-start circuit, but I need a 120 / 240 volts version.
Can you accept to send me the schematics. This way I will be able to modify and adapt it to my needs.
Thanks
AL
Hi Dante
I haven't got a schematic in a form that I can easily post at this stage, but I will get around to it (another thing on the list...).
The bare PCBs I can do for US$20 each. I'll work out today the price for all the parts & PCB, and then also fully assembled and get back to you.
P-A is correct - the transformer has dual 110V primaries, so you would need to cut a track and parallel the windings. One other change is necessary - you would need to change a couple of compnent values in the voltage divider section for the soft start, but that would be straightforward.
I haven't got a schematic in a form that I can easily post at this stage, but I will get around to it (another thing on the list...).
The bare PCBs I can do for US$20 each. I'll work out today the price for all the parts & PCB, and then also fully assembled and get back to you.
P-A is correct - the transformer has dual 110V primaries, so you would need to cut a track and parallel the windings. One other change is necessary - you would need to change a couple of compnent values in the voltage divider section for the soft start, but that would be straightforward.
Hi ab
Not sure. Dimensions of the Block FL6/6 are 53x44. Datasheet with pinouts etc are here http://docs-asia.electrocomponents.com/webdocs/0027/0900766b8002776f.pdf
The Block FL6/6 is available from RS Components for about A$25 - probably not much different to the price of the Jaycar one. The heatsink I used was from Jaycar. The relays are RTB34012F (Digikey PB362-ND) and RTB34024F (Digikey PB363-ND), about US$3.40 a piece. You might be able to find another replacement for these as well, but I chose them as they are rated at 12A/3000VA. Everything else is pretty bog standard and can be sourced from Jaycar.
Not sure. Dimensions of the Block FL6/6 are 53x44. Datasheet with pinouts etc are here http://docs-asia.electrocomponents.com/webdocs/0027/0900766b8002776f.pdf
The Block FL6/6 is available from RS Components for about A$25 - probably not much different to the price of the Jaycar one. The heatsink I used was from Jaycar. The relays are RTB34012F (Digikey PB362-ND) and RTB34024F (Digikey PB363-ND), about US$3.40 a piece. You might be able to find another replacement for these as well, but I chose them as they are rated at 12A/3000VA. Everything else is pretty bog standard and can be sourced from Jaycar.
Hi AL
You need to change the mains cap from 0.33uF to 0.68uF, assuming 110V/60Hz (if my calcs are correct), to drop the correct voltage, which in your case is about 80V. This must be a mains rated cap (X1/X2). I used a Vishay MKP 338 series X1 cap (Digikey BC1595-ND for the 0.33uF).
If the power is lost, the relay is no longer energised, so defaults to the off position. When the power returns it is still in the off position until you press the on switch again (ie it is not latching - the coil is energised while the amp is "on")
You need to change the mains cap from 0.33uF to 0.68uF, assuming 110V/60Hz (if my calcs are correct), to drop the correct voltage, which in your case is about 80V. This must be a mains rated cap (X1/X2). I used a Vishay MKP 338 series X1 cap (Digikey BC1595-ND for the 0.33uF).
If the power is lost, the relay is no longer energised, so defaults to the off position. When the power returns it is still in the off position until you press the on switch again (ie it is not latching - the coil is energised while the amp is "on")
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