Soft switch version 2
Original Thread:
https://www.diyaudio.com/forums/showthread.php?s=&threadid=61653
The "Soft Switch" is a circuit that uses a momentary contact switch to switch the AC power for audio power amplifiers and preamplifiers. It uses a flip-flop to turn a relay on and off. The included switch has a brushed metal finish and mounts flush to the surface. It has a blue LED ring surrounding the button to indicate if the amp is powered on.
You can find more info and pictures on my website:
https://www.robcheng.com
Click on AUDIO -> ELECTRONICS -> SOFT SWITCH V2
Updates
| 09-Aug-2005 | Close date extended to end of August. |
| 02-Aug-2005 | Finalized pricing and GB close date. Now accepting payments. |
After the first group buy of the soft switch circuit, I continued to get emails from people interested in the kit. I've made a version 2 which includes the following improvements:
1. Replace the hard-to-obtain MAX6816 (debounce IC) with a CD4013.
2. Added a high current relay to switch up to 15A AC.
3. Added jumpers to make one board work with 115VAC and 230VAC.
4. Added an NTC thermistor for in-rush current limiting. The layout supports the popular CL-60 or larger CL-101 part.
5. Added a fuse (15A max) for the switched output.
6. Added an output for an optional current-limiting board.
Pricing
Since most everyone who has responded so far wants more than one kit, I've lowered the individual pricing to keep the math simple, rather than complicate shipping charges with multiple kits:
$50 shipped (U.S.) for soft switch kit.
$35 shipped (U.S.) for soft switch kit minus switch.
$10 shipped (U.S.) for soft switch PCB only.
$25 shipped (U.S.) for soft start kit.
The prices are higher than the previous GB because I'm including the transformer and high-current relay. This kit is a solution to allow minimal effort to implement a premium switch for your prized DIY amp and offers a neat and professional look.
Preferred payment method is via Paypal (to rcheng.at.mindspring.com).
I am now accepting payments. Please add 2.9% + $0.30 to cover my paypal fees.
Example:
If you want 2 soft switch kits, the price will be $100. Add 2.9% + 0.30 and the total is $103.20.
For international orders, typically the shipping will be about $5-$10 more depending on the location. I will have to figure shipping individually via email.
Due to an unplanned 2 week trip for work out of the country, I will be extending the group buy deadline until the end of August. I plan to order parts the first week of September.
| Name | Kit no switch | Kit with switch | Opt soft start | PCB only | Location | Paid |
| DW8083 | 0 | 2 | 0 | 0 | USA | yes |
| Brian Bell | 0 | 0 | 0 | 0 | USA | |
| Chuck | 0 | 6 | 0 | 18 | USA | yes |
| DaveN? | 0 | 2 | 0 | 0 | | Yes |
| Chipco3434 | 0 | 2 | 0 | 0 | USA | yes |
| GeWa? | 1 | 1 | 0 | 2 | BE | yes |
| Coulomb | 1 | 0 | 2 | 2 | CAN | |
| Billc | 0 | 2 | 2 | 6 | USA | yes |
| MattM? | 0 | 5 | 0 | 0 | USA | yes |
| jonk | 0 | 2 | 2 | 0 | CAN | yes |
| W.O.L.F. | 0 | 1 | 3 | 2 | Ger | yes |
| Argofanatic | 0 | 8 | 8 | 0 | CAN | |
| dr.Strangelove3 | 0 | 2 | 0 | 0 | NL | yes |
| AR2 | 0 | 4 | 4 | 0 | USA | yes |
| Cobra2 | 2 | 0 | 0 | 0 | NORWAY | yes |
| Mike2 | 1 | 0 | 0 | 1 | USA | yes |
| Seth Hensel | | 2 | 0 | 0 | USA | yes |
| Sander | 0 | 1 | 1 | 0 | NL | no |
| t3rrence | 0 | 1 | 0 | 0 | USA | no |
| rjkdivin | 1 | 1 | 4 | 0 | USA | yes |
| | | | | | | |
| | | | | | | |
| Totals | 5 | 38 | 22 | 28 | USA | -- |
