+hloberg Posted October 25, 2020 Share Posted October 25, 2020 my project blog post of what I did to create it: Notes: the biggest thing for me was finding out you only needed to attach 1 positive and 1 negative even though it shows 3 & 3. and a 5 pin DIN can work just fine. Also, as I posted, I used an old USB powered hub for the power supply. A phone charger may or may not work. I have found some phone chargers to be very cheaply made an the voltage can fluctuate. Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted October 25, 2020 Share Posted October 25, 2020 Nice work! It is indeed nice to power the Atari from a modern compact, cool power supply. The danger of using a 5-pin DIN is the possibility of accidentally plugging it into the monitor jack. 7-pin DIN's are readily found on ebay. Usually 3 pins are connected to each of the +5vdc / GND to help improve conductivity through all 3, as the original power supplies had nice fat AWG cable with little impedance compared to USB cords nowadays. It's really only 1 power supply that was notorious - the "ingot" . Most (all?) of the others are still quite reliable and servicable being simple transformers with conventional voltage regulators - only downside being their bulk and relative inefficiency. Most of them will technically produce smoother DC power than modern switching supplies. 1 Quote Link to comment Share on other sites More sharing options...
+hloberg Posted October 25, 2020 Author Share Posted October 25, 2020 1 hour ago, Nezgar said: Nice work! It is indeed nice to power the Atari from a modern compact, cool power supply. The danger of using a 5-pin DIN is the possibility of accidentally plugging it into the monitor jack. 7-pin DIN's are readily found on ebay. Usually 3 pins are connected to each of the +5vdc / GND to help improve conductivity through all 3, as the original power supplies had nice fat AWG cable with little impedance compared to USB cords nowadays. It's really only 1 power supply that was notorious - the "ingot" . Most (all?) of the others are still quite reliable and servicable being simple transformers with conventional voltage regulators - only downside being their bulk and relative inefficiency. Most of them will technically produce smoother DC power than modern switching supplies. the fact you could accidentally plug it into the monitor port I didn't even think about till you pointed it out, thanks. Something to watch for on the 800XL and upgraded 600XLs (does the 1200XL have the same 7 pin connection?). And, yes, way back when I had an 800XL I went through several of those 'ingot' power supplies which left a bad taste. My biggest issue with the 'ingot' were they sometimes only partial went out giving all kinds of weird problems and if you checked them they would still look OK on a multi-meter. I had one do that and gave me video issues. I tore than machine apart trying to fix the problem till I figured out it was that !@*^#! power supply. 1 Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted October 25, 2020 Share Posted October 25, 2020 53 minutes ago, hloberg said: (does the 1200XL have the same 7 pin connection? 1200XL uses same 9VAC power supplies as 400, 800, 810, 1050, etc. The problem with the "ingot" is that they are known to fail not just undervolting, but outputting 9-12V AC, which has fried untold numbers of XL/XE machines that have no internal protection against this. ? RAM is the first to go, then if you're unlucky maybe other IC's... Quote Link to comment Share on other sites More sharing options...
+hloberg Posted October 25, 2020 Author Share Posted October 25, 2020 18 minutes ago, Nezgar said: 1200XL uses same 9VAC power supplies as 400, 800, 810, 1050, etc. The problem with the "ingot" is that they are known to fail not just undervolting, but outputting 9-12V AC, which has fried untold numbers of XL/XE machines that have no internal protection against this. ? RAM is the first to go, then if you're unlucky maybe other IC's... yes, fun little devices. I was lucky none of mine bricked my computer like I heard it had on other Ataris. Quote Link to comment Share on other sites More sharing options...
+slx Posted October 26, 2020 Share Posted October 26, 2020 9 hours ago, Nezgar said: The problem with the "ingot" is that they are known to fail not just undervolting, but outputting 9-12V AC, which has fried untold numbers of XL/XE machines that have no internal protection against this. ? RAM is the first to go, then if you're unlucky maybe other IC's... Are there any mods (like adding a fuse) to prevent wrong (C64?) or faulty PSUs from damaging XL/XEs? Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted October 26, 2020 Share Posted October 26, 2020 2 hours ago, slx said: Are there any mods (like adding a fuse) to prevent wrong (C64?) or faulty PSUs from damaging XL/XEs? Probably not worth the effort, if you have an Ingot, just bin it, probably cheaper than doing some sort of mod on the XL/XE. I don't know about the C64 PSU, I assume it has a similar plug, all I can say is "just be careful" Quote Link to comment Share on other sites More sharing options...
shoestring Posted October 26, 2020 Share Posted October 26, 2020 3 hours ago, slx said: Are there any mods (like adding a fuse) to prevent wrong (C64?) or faulty PSUs from damaging XL/XEs? You can add a crowbar circuit to any XL/XE power supply as long as you can get inside . I based my build on the following circuit below, I built two, one for my c64 and Atari power supplies but I decided on a 5.6v zener instead of 6.3v and a LM2596 buck module instead of the original 7805. When the output voltage from the 7805 exceeds ~5.6v the zener begins to conduct and the SCR is switched on, it then shorts the DC input to the 7805 to gnd and this blows the fuse which is in line with it. You can easily build this to have a very small foot print on some vero so it can easily fit inside the power supply case. http://www.electronicecircuits.com/electronic-circuits/7805-5v-1a-regulated-power-supply-with-overvoltage-protection-circuit 2 Quote Link to comment Share on other sites More sharing options...
Gunstar Posted October 26, 2020 Share Posted October 26, 2020 (edited) If you intend to have several upgrade boards in your Atari, I recommend something with more than 1 amp. That's why I prefer the Atari "universal" PSU's rated for 31VA (3.4A), as there's still plenty of amperage left for upgraded machines. One day soon I'll be adding more upgrades to my 1200XL, including a 3.5" internal floppy, and I'll be forced to lose the 1200XL's power circuitry and heat-sink. For example: https://www.amazon.com/ALITOVE-100V-240V-Converter-5-5x2-1mm-Security/dp/B078RXZM4C/ref=sr_1_6?dchild=1&keywords=5vdc+3a+power+supply&qid=1603715564&sr=8-6 Edited October 26, 2020 by Gunstar Quote Link to comment Share on other sites More sharing options...
shoestring Posted October 26, 2020 Share Posted October 26, 2020 I couldn’t find any above 2a apart from a psp-100 charger I have as a backup. Its a little noisy though compared to my rebuilt ones. The lm2596 can drive 3a without a heat sink. It has a trim pot so you can tweak the output voltage. I looked at other alternatives, drop in replacements but the c64 is hungry, especially with an Ultimate 1541 II+ Cart. The power supplies run cooler, especially the A8 version. 1.5 years later and still going strong. 1 Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted October 26, 2020 Share Posted October 26, 2020 2 hours ago, shoestring said: You can add a crowbar circuit to any XL/XE power supply as long as you can get inside Nice protection circuit, but that would need a circuit board and some track surgery inside the XL/XE, also you couldn't use a normal PSU as this needs at least 7V to work, so your already replacing the external PSU. I suppose you could buy a case that could house the 7V supply and the new circuit, then that would be ideal and it would provide some nice protection. Not knocking your idea, it's a nice thing to have ? Quote Link to comment Share on other sites More sharing options...
+hloberg Posted October 26, 2020 Author Share Posted October 26, 2020 wouldn't a simple 2 amp in-line fuse cut into the line be enough? Quote Link to comment Share on other sites More sharing options...
+Stephen Posted October 26, 2020 Share Posted October 26, 2020 24 minutes ago, hloberg said: wouldn't a simple 2 amp in-line fuse cut into the line be enough? No. When the ingots fail and go way overvoltage, there is no guarantee that the machine will draw more than 2 amps. Not at least, until it has been damaged in multiple places. 1 Quote Link to comment Share on other sites More sharing options...
shoestring Posted October 26, 2020 Share Posted October 26, 2020 9 hours ago, TGB1718 said: Nice protection circuit, but that would need a circuit board and some track surgery inside the XL/XE, also you couldn't use a normal PSU as this needs at least 7V to work, so your already replacing the external PSU. I suppose you could buy a case that could house the 7V supply and the new circuit, then that would be ideal and it would provide some nice protection. Not knocking your idea, it's a nice thing to have ? No surgery is needed in any machine. Im not really following you here on the 7v thing. The module can accept 4vdc-40dc, the 12vdc input voltage is supplied by the transformer after rectification which is then fed into the regulator ( 7805 or in my case the buck module ). As I said, it can have a Very small foot print and easily fit inside an existing power supply. Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted October 27, 2020 Share Posted October 27, 2020 13 hours ago, shoestring said: The module can accept 4vdc-40dc, No, minimum input voltage is 7VDC to Max 35VDC you won't get a regulated 5VDC output from a 4VDC input, it's not a voltage multiplier. But as I said, nice to have, not knocking it at all (I misunderstood your first post, thought you implied it was fitting inside the XL/XE) Quote Link to comment Share on other sites More sharing options...
shoestring Posted October 27, 2020 Share Posted October 27, 2020 (edited) Have a look at the data sheet. I think you’re confusing the fixed 5v version for the adjustable version I’m using. There’s actually several versions of the chip, one being adjustable the others fixed ( 3.3, 5, 12 and adj ) It accepts an input from 4.5v - 40v. The module has a trim pot for tweaking the output. btw... Who said anything about feeding the chip with 4v to get 5v out? I was simply describing the specifications of the device. Edited October 27, 2020 by shoestring Quote Link to comment Share on other sites More sharing options...
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