Power control and startup boards

[Nick]

After I mentioned the way I was controlling the power in on my phono stage using an always on controller board, a push button switch and solid state relay I have been looking at making a PCB up to do all the above, given the wonderful world of PCB making, it seems to cost much the same to get 50 made as 10, but in all cases its more than I would like to spend to have them sitting on the shelf. So I thought I would see if there was any other interest, they would be at cost, and I think they should work out at less than £20 each (thats at the 20 or more boards point) populated and programmed. There is about £7 worth of parts to add. All that would need adding is the push switch and solid state relay of your choice, or you could populate yourself and I will just add the cost of the controller and flash it before sending.

Just a thought.

[Andrew]

Could you elaborate on the spec again?

Am I correct in assuming you press the on switch, the controller then senses this, then it fires the user's relay, or relays, which connected externally, via a set of driver transistors on the PCB?

The board includes the driver transistors, DC power supply, mains transformer and controller?

If you're going to all this trouble, and if its possible, wouldn't it make sense to allow for controlling two sets of relays with say a 45 sec delay between each. That would solve many of the folks on here issues with delayed switch on etc to allow the heaters to come up. In fact, three relays might be even better, one for the heater, one for the HT and the last one for the mute. Just a thought, seems for £20 it would be worth adding the extra features, tho perhaps two is enough.

Andrew

[Mike H]

Does it not do:

PRESS #1

power on, some interval later, mute off (a second relay)

PRESS #2 (again)

power off

So long as the delayed relay operation is adaptable enough so could be used for something like putting the HT on after heaters warmed-up, yes I'd be interested, so would a few other folks I expect



 

[Nick]

Well, its all soft, but what I had in mind was

1. Debounced switch input. Press to start warmup

2. led output starts flashing, 5v output to first SS relay goes high, powers up heaters

3. After delay (15, 30, 45, 60 sec, I have a jumper header on board that could select this time) mute relay (on board) opens, led stops flashing and is full on

Then the jumper can select a second phase, if the jumper is selected

3. After first delay, second 5v output goes high, powers second SS relay to power B+ transformer, or drive a offboard relay to connect B+ secondary

4 after second delay, mute relay opens, led stops flashing. everything is on

On second press on switch, all goes back to off condition (at any point in the startup cycle), on power interruption (brownout detection) it resets to initial off state.

I have also got a enable input, when open nothing powers up, I have used this in the past for two box designs, so unless the amp and the power supply and connected nothing starts, or if they are disconnected it shuts down.

I have only included drivers for the mute relay, as I dont want to use the board to power any external relay, as then the board power supply needs to provide more power, which means there is more iron loss so more standby current is used.

I will post the schematic tonight and it may make more sense.

[Nick]

The current PCB quote I have works out like this:

10 off total £182.50 + vat = £18.25 + vat each
20 off total £182.60 + vat = £9.14 + vat each
50 off total £194.00 + vat = £3.88 + vat each

The parts to populate at Rapid prices come to about £6 + vat, and the only non standard bit is the processor which is £1.40 ish, and I would just run through the programmer before sending them out, only take a minute or so each one.

The only bit of the above that I am trying to get a few interests of is the PCB's to get the unit price down, but I can do like Mike did with the eCap board and send out kits of parts with the boards if wanted.

[Mike H]

All sounds alright to me!


Can put me down for a couple



 

[pre65]

Sounds like a good idea, but for me I think it's just too "technical", takes me out of my comfort zone.

Thanks muchly for the offer though.

[James]

Hi Nick,

I would be up for a couple as well.

Thanks,

James.

[ed]

I'll spend £18 if I may.......will I get 1 or 2 boards if ts a goer?

[Nick]

Depends on numbers, I can say for certain when I get a idea of totals, you can always change your mind later if its too spensive.

[simon]

I'll try a couple too, hoping we get to 20 boards. Kits work for me .

[Mike H]

Sounds like a good idea, but for me I think it's just too "technical", takes me out of my comfort zone.

I think it's the description that's confusing you.

Press button, heaters start up, X seconds later, HT starts up

Seemples!



 

[pre65]

Sounds like a good idea, but for me I think it's just too "technical", takes me out of my comfort zone.

I think it's the description that's confusing you.

Press button, heaters start up, X seconds later, HT starts up

Seemples!

Not really needed with 6D22s damper diodes ?

I think the simple (read basic) way is for me.

[Mike H]

I take your point re the 6D22's



 

[ed]

Depends on numbers, I can say for certain when I get a idea of totals, you can always change your mind later if its too spensive.

it was the quotes that fascinated me...if you get 10 people then we pay £18 give or take then some body finds another 10p and we all get 2 boards.....simples