| Posted By
JledStev61
on 2020-09-04
23:45:57
|  Questions about Plus4 Saver
Hello Plus4world
Scored a cheap deal on a plus4 from eBay.
Works but before I give it more testing
I want to guard against the brick of death.
Finally found an electronics store that sold actual components.
I want to build a Saver using Ray Carlsen's design.
I also wish to add modern power supplies (so there will be two options)
5v 2amp, and AC to AC 9volt 1amp.
At the store they sold me both.
Accept when I went back in the room for a zener diode,
he switched the 5v 2 amp for a 3amp.
WTFudge?
I didn't know this till I was walking out the door,
and he tells me he switched the power supply because the
first one was the wrong voltage.
Mind you he picked them out in the first place.
When I got back home it turns out the new 5volt
power supply is a 3amp.
And $5 dollars more expensive.
That's why he switched it.
But I just wanted the 2amp.
For the saver I got an SDR-05VDC-SL-C,
and a smaller 2amp relay.
The Saver is not needed for the newer power supplies,
but I wanted to add the option anyways.
My idea is to put the relay inside the Plus4.
And just before the Saver, along the + hijacked power line,
also add the option of the alternative modern supply.
This way the saver could also monitor the newer supply.
Probably not necessary.
I've never built one of these before.
The 2amp relay is smaller then the 4amp,
and would prefer to place that one inside.
If I use a 5v 3amp supply,
would the 2amp relay be able to handle it?
If the 2amp can't handle the 3amp supply,
I will have to add the alternative power after the saver.
Or, as I am hoping, it doesn't matter what the amps of the supply,
and the 2amp relay will handle it anyways.
(By the way if you don't know, never use more then one supply at the same
time. Well, unless its just the 5v and 9vac)
Instead of drilling holes for the newer supplies, (yuk)
I will just have a detachable lead going out the cartridge port hole.
For Ray Carlsen's saver, he never says what voltage rating the LEDs
should be. I have two 5volts red and green.
Someone somewhere said to add a diode to LEDs to prevent shorting.
I forget where.
The schematic says to use 1k resistors leading to the LEDs.
What voltage should the LEDs be?
I can't find any information about the LEDs other then
they can be used to show which way the relay is pointing.
Also I bought an NTE960 to replace the 7805.
But I cannot find one in the plus 4,
At least according to the service manual as yet.
I see a similar component at Q4,
but this is not bolted to any medal plate as the C64 has.
So I think this must be another circuit.
Could it be that for the Plus4 the 7805 is only in the power brick?
About the shield, would you leave it or remove it?
I can imagine it preventing extra air.
Any thoughts would be appreciated.
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Posted By
kopsec
on 2020-09-06
18:02:03
| Re: Questions about Plus4 Saver
I think you'd better replace the power connector in the Plus4 and install a C64 one.
See here: http://hackjunk.com/2017/05/29/commodore-plus-4-power-connector-to-c64-version/
Then you can use any of the thousands of savers for C64, or make your own one using the more standard 7 pin DIN connector of C64. The backside is that you need a C64 power supply or change the connector, but if you are doing a new power supply, just fit a 7 pin DIN.
The Plus4 doesn't have a 7805 inside, it takes the 5V from power supply, where is located the 7805 or similar.
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Posted By
JledStev61
on 2020-09-07
00:07:15
| Re: Questions about Plus4 Saver
[I think you'd better replace the power connector in the Plus4 and install a C64 one.]
Is a good idea. But I only have a Plus4 supply.
I am hesitant to cut it for putting in the saver in the cord.
Otherwise I will have to find another 4pin din for an external saver.
That seems to be hard part going about it.
Maybe I think I just to put the saver inside the Plus4.
[The Plus4 doesn't have a 7805 inside]
Oh. That is why I did not find one.
But I think there is one inside the C16. Unless I am mistaken.
Also the 64 of course.
About my LEDs, I can not figure the ballast resistance for my LEDs.
C= powers supply = v5
LED Vf = 5v 10ma
5 - 5 = 0 / .01 = 0
So no resistance?
But everyone says there still needs to be resistor anyways.
I don't know why the LED is rated so high in volts. (they are labeled superbrite)
I may just buy different ones.
Or just put a 470 to it anyways.
My multimeter won't measure it like it does the 2volt ones I have.
Package says it is 5Vf.
And about the relay.
I will just use the SRD-05vdc-sl-c instead
and it will use the amps fine anyways.
I looked at your DIAG 264 and really intrigued.
When I get my situation settled I will get one of those for sure.
And that was interesting what plugged into the keyboard slot.
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Posted By
MMS
on 2020-09-07
13:47:41
 | Re: Questions about Plus4 Saver
Actually if you do NOT need deperately the 3+1 and the User port, then a 64KB C16 is a better solution.
Especially due to the cheap PSU solutions you can have for C16.
It can 100% utilize the ZX Spectrum PSUs, the 128K and the Grey +2 are the best, they have enough power to manage cassette and extra adaptors. Their PSU's connector and polarity fits perfectly to the C16. But any PSU brick with 1.5 - 2.0 A and 9V would do the job.
I think the C16 PSU is unregulated (and underpowered)), but with a regulated (switch mode) DC adaptor you may also reduce the heat gereated insiode the housing.
But maybe I am wrong, so the hardware gurus will correct me  Please!
Sure, the regulator heats up more than in Plus/4 (it has to create the 5V from the 9V DC), but the housing is much bigger and has more air around the hot ICs (not to mention, there are less ROMs generating extra heat)
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Posted By
JledStev61
on 2020-09-07
14:49:57
| Re: Questions about Plus4 Saver
I also have a 1/2 inch fan.
In pictures Ray Carlson connected to the C1 capacitor.
I'm not sure what he used as a board for his Saver.
Is it a grounding plate?
Should I use an unclad matrix board?
I have enough parts to make several versions.
For the trimmer resister version I do not have a non-polar capacitor.
But I hear if you put two capacitors together it will create
a non-polar capacitor.
The other requires no capacitors.
The c16 PSU is 9vdc only. Is this correct?
And center negative.
I can imagine many c16s are busted for people placing the wrong psu.
Want to hear a horror story?
I had a c16 once.
At a pawn shop I found a large box that looked discarded in the corner.
Curious I opened it and found a treasure.
A 1080 monitor.
2 data cassettes, one brown,
which I know today is the 1531.
A 1541 and 71 and a case of old software.
I removed these things to see what else was in the box...
A c16, a plus4, a c64 (the flat one and first I'd ever seen)
a 128, all the PSUs. A mouse.
Lots of cartridges and tapes.
The brown and white modems.
Probably more too but I can't recall all of it.
The entire box was $15.
I bought it brought it home.
This was 2002, before eBay, before YouTube.
Even though I had some of them before,
in 2002 I just considered them antiquated
and ended up giving them to a friend.
Today I kick myself for that decision.
At the time only diehard C= fans still cared about them.
Had never seen the C16 before.
When I found a power supply (center negative),
It just showed a black screen.
Everything else worked but I never tested the 1531.
I hate thinking about it today.
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Posted By
JledStev61
on 2020-09-09
02:32:39
| Re: Questions about Plus4 Saver
I have several 5v adaptors now.
And one of the Sony 5v adapters I've seen in some videos.
It is rated at 5.2vdc 2amps.
Plus another 2 amp 5.1vdc
And my original 5v 3amp power supply.
I bought wire up connectors for my adapters.
Just screw in the wires.
I thought to solder 4 wires from the underside of the motherboard under the power jack.
(Getting the shield off is a M****F*****)
I tested 4 pins. The 2 ac 9v pins,
and the dc 5v pins.
I plugged in the brick of death but made sure the power switch was off.
The dc came in at 5.2v (from the brick of death).
The AC came in at 10.4v.
But the power jack/port has 6 pins, I believe.
Two of which, at the edge seems to be soldered to the ground rail.
And I if there is something I'm missing there, I will put it off.
The rest of my components won't arrive for another week before I can build a Saver.
If I wanted to I could cut the +4 PSU near the connection and wire the remaining
up to my adaptor connector jacks.
It is reversible and could hide the split with some heat shrink.
Another thing to note is that Ray Carlsen built his saver on a plus4 that had the c64 jack conversion.
Which is just slightly smaller the the plus4 jack.
And he suggest cutting the positive 5V rail so it can be hijacked by an internal saver.
However because of his C64 Powerjack conversion, he had a bit more room to make the split.
The space there is very tiny with a Plus4 jack still installed.
Because of that I was thinking if I cut the brick's cord,
I could just build the saver into it.
And in the meantime use my other adapters with the remaining cord.
kopsec's advice would be a good consideration.
Not only would I have more access to the rail,
But I could build a saver with a C64 jack,
and use my de-soldered plus4 jack as the input for the saver.
In that case I would never have to cut any cord.
It would be:
(Plus4 with C64 power jack) to (C64 male din) leading to (saver) receiving power from (plus4 powerjack) to (plus4 power brick)
Downside is waiting for the mail to deliver both male and female C64 power connector and Din.
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