power plug xl/xe

[oo7]

Hi Guys,

 

 

I need a power supply for a 65 XE I just purchased (on its way). So Im going to just make one. (Well put a plug on a good sony one I have 5v 2 amps)

 

Im going to order this plug https://www.digikey.ca/en/products/detail/cui-devices/SD-70/97001

 

Shockingly local electronic stores dont seem to have one.

 

 

Am I correct this plug will fir the XE perfectly? (i believe i need 7 pin din 270 degrees)

 

 

I already know that I need to hook up 

 

Pin 1 +5V

Pin 2 not connected (should be shield)

Pin 3 Ground

Pin 4 +5V

Pin 5 Ground

Pin 6 +5v

Pin 7 Ground

 

 

Been bit by the atari 8 bit bug again.

 

Altirra got me back into the 8-bit line. since then got the wifes 400 hooked up. My 130xe is missing long story and now I just bought a 65 xe for me to get seriously back into this platform.

 

 

 

[carlsson]

Yes, 270 degrees is correct. DIN connectors in general seem to be somewhat outdated so I'm not surprised that local resellers don't stock them, or at least variations with more than 5 pins.

[Rybags]

If you're feeling lazy you can get away with wiring just 2 pins - that's how my XL PS has been since new.

The pins are likely capable individually of carrying at least 5 times what the leads could so it's not like there'd be a problem anyway.

[oo7]

Thanks guys

[gilsaluki]

this works well for the power source.

https://www.amazon.com/gp/product/B005T6UJBU/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

 

[oo7]

1 hour ago, gilsaluki said:

this works well for the power source.

https://www.amazon.com/gp/product/B005T6UJBU/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

 

hmm thanks for the suggestion, will try it if my sony one doesnt work out.

[hasanc]

28 minutes ago, oo7 said:

hmm thanks for the suggestion, will try it if my sony one doesnt work out.

You could also try using an USB cable. It works fine on my 600 and 800XL with a few extensions attached (e.g. SIDE 3 and FujiNet).

[carlsson]

3 hours ago, Rybags said:

The pins are likely capable individually of carrying at least 5 times what the leads could

True. On the Commode side, the 5V line usually is rated for 1.5 - 1.7A, on heavy duty up to 2.5A on a single pin. That one has 9V as well for some functions, but the amperage on 5V still is this high from one wire and one pin. Now perhaps the interior part of the power circuit is fundamentally different on Atari and e.g. C64 which would explain why the Atari prefers to divide it onto multiple pins. Or is the XL/XE specified to be able to pull some 5-6A if peripherals need and the power supply can withstand it?

[oo7]

5 hours ago, carlsson said:

True. On the Commode side, the 5V line usually is rated for 1.5 - 1.7A, on heavy duty up to 2.5A on a single pin. That one has 9V as well for some functions, but the amperage on 5V still is this high from one wire and one pin. Now perhaps the interior part of the power circuit is fundamentally different on Atari and e.g. C64 which would explain why the Atari prefers to divide it onto multiple pins. Or is the XL/XE specified to be able to pull some 5-6A if peripherals need and the power supply can withstand it?

Since the 400 and 800 and 1200 xl run on a siingle barrel im thinking thinking it was more done due to either availability or to seem special. Most atari boards i been looking at online seem to bring the 4 together almost immigrated on the board

[adam242]

Also, you can just use a 5-pin DIN plug. It will fit.

 

If you do, just be very careful you never plug it into the monitor jack by mistake! This is likely why Atari chose to use a 7-pin for the power supply, to prevent people from accidentally frying their machines.

[oo7]

15 minutes ago, adam242 said:

Also, you can just use a 5-pin DIN plug. It will fit.

 

If you do, just be very careful you never plug it into the monitor jack by mistake! This is likely why Atari chose to use a 7-pin for the power supply, to prevent people from accidentally frying their machines.

Good to know 5 pin would fit but ya that would be a good way to blow it up.

 

I ordered from digikey have a proper 7 pin 270 degree and a 5 pin 180 degree arriving tomorrow. I mainly posted to make sure i was right on the specific din that is most proper. I plan to clean up the xe im getting and use it as an original no mods. My only deviation will be a devive to allow loading off of sd or flash other than that i aim for authentic feel and look. 
 

 

[+DrVenkman]

If you have an existing XL/XE PSU that you don't intend to use (e.g., an Ingot) the easiest solution is to cut off the DIN jack pigtail and re-wire it to a modern power supply. That saves the ever annoying task of soldering a new DIN jack connector. 

[gilsaluki]

On 8/5/2021 at 7:39 PM, DrVenkman said:

If you have an existing XL/XE PSU that you don't intend to use (e.g., an Ingot) the easiest solution is to cut off the DIN jack pigtail and re-wire it to a modern power supply. That saves the ever annoying task of soldering a new DIN jack connector. 

that's what I did with this unit.  EZ. 

https://www.amazon.com/gp/product/B005T6UJBU/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

[oo7]

So this is done, all 6 pins used, shield not used.

voltmeter reads steady 5.25volts with no load, will report under load later if anyone is curious

[+DrVenkman]

5.25V is on the very high end of “acceptable” for most of the chips used in the Atari. If that PSP adapter is a switching power supply (not just a transformer/rectifier deal like a vintage Atari PSU), then it’s unlikely the voltage will drop much under load.

 

So be very, very careful with using that supply until you’re certain it’s stable. And if you see any glitching or weirdness (hum, rolling bars or artifacts in the video), pull the power immediately. You might look instead to a USB power brick. They’re already designed to provide stable 5V DC power and you can find them up to 2.5A or more pretty cheaply. 

[oo7]

50 minutes ago, DrVenkman said:

5.25V is on the very high end of “acceptable” for most of the chips used in the Atari. If that PSP adapter is a switching power supply (not just a transformer/rectifier deal like a vintage Atari PSU), then it’s unlikely the voltage will drop much under load.

 

So be very, very careful with using that supply until you’re certain it’s stable. And if you see any glitching or weirdness (hum, rolling bars or artifacts in the video), pull the power immediately. You might look instead to a USB power brick. They’re already designed to provide stable 5V DC power and you can find them up to 2.5A or more pretty cheaply. 

I own many charging bricks already. I just thought an PSU is better than a USB charger.

 

 

Maybe I will do this.

 

I thought 5.25 was high compared to what I wanted.

 

Havnt used it yet. Maybe I will try a different supply or as you said go usb.

 

I guess I should aim for <5.1??

 

 

I have a few 5 vdc switching supplies with 3 amp rating I just measured one at 5.16 volts. AMPs are double OEM but that said amps is more of a demand factor. This might be a better option?

 

I have debated seeking a real atari supply but I was thinking using a newer PSU is much safer if done right.

 

Thoughts?

 

 

WHat would idea min max off load and min max on load be?

 

 

Generally off load I shoot for -0 to +5% and this supply is showing 5% lol I had it monitored for 10 min no load at steady 5.25

 

Since Im dealing with an old machine known to be sensitive I should aim for -0/+2% off load and -0/+1% on load?

 

 

To test on load I plan to probe either the joystick ports and or sio port. (does this make sense?)

 

 

 

 

 

Edited August 12, 2021 by oo7

[TGB1718]

Best way to test your PSU's is to use a low value/high wattage resistor across the 5V and 0V lines

something like a 5 ohm 10 watt resistor will pull 1 Amp, and measure the voltage under load,

bear in mind it will get extremely hot while your doing this.

[oo7]

2 hours ago, TGB1718 said:

Best way to test your PSU's is to use a low value/high wattage resistor across the 5V and 0V lines

something like a 5 ohm 10 watt resistor will pull 1 Amp, and measure the voltage under load,

bear in mind it will get extremely hot while your doing this.

Might try this. Ill post if I do.

[+DrVenkman]

2 hours ago, TGB1718 said:

Best way to test your PSU's is to use a low value/high wattage resistor across the 5V and 0V lines

something like a 5 ohm 10 watt resistor will pull 1 Amp, and measure the voltage under load,

bear in mind it will get extremely hot while your doing this.

 

6 minutes ago, oo7 said:

Might try this. Ill post if I do.

Beware. Most resistors you’re likely to have lying around are going to be rated for a hell of a lot less that 10 watts. Most are going to be 1/8 or 1/4 watt max. Be careful not to set anything on fire.

[oo7]

2 minutes ago, DrVenkman said:

 

Beware. Most resistors you’re likely to have lying around are going to be rated for a hell of a lot less that 10 watts. Most are going to be 1/8 or 1/4 watt max. Be careful not to set anything on fire.

Lol i would order one like he specked from digikey

 

thanks for the heads up

[carlsson]

How much load would connecting an incandescent light bulb to 5V generate?

[+DrVenkman]

6 minutes ago, carlsson said:

How much load would connecting an incandescent light bulb to 5V generate?

V=IR

 

How much current are you supplying and what’s the resistance of the bulb? 

[carlsson]

A light bulb is non-Ohmic though.

 

Quote

Tungsten has a cold resistance of 9.6 ohms at 100 watts. If 120 volts is applied, using ohm’s law we get a current of 12.5 amps. But, the temperature of the tungsten heats up and so does its resistance. At the same voltage of 120 volts the resistance increases to 144 ohms and the resulting current is 0.83 amps. As you can see the resistance of the filament changes and therefore is classified as a non-ohmic resistance. 

 

Also, if a greater voltage is applied to the light bulb, the temperature of the filament is going to increase and its resistance is going to decrease. The light bulb’s resistance will change with varying temperatures and voltage, which is not ideal for an electrical or electronic circuit as it will require a constant resistance.

 

But the idea was not to permanently implant a light bulb into a circuit, but to have something to generate a load to see how the voltage from the power supply acts.

 

Edited August 12, 2021 by carlsson

[_The Doctor__]

The incandescent bulb is a very valued tool when installed in series not parallel on the  power line of a crt or other such devices during diagnosis and repair, so that broad statement has it's exceptions for sure.

[+DrVenkman]

Yes, I know very well what a dim-bulb tester is.

 

However, the question as stated is not helpful because the answer depends on the size and characteristics of the bulb being used to generate the load on the circuit. And, as pointed out above, as the tungsten heats up, resistance goes down.