Two Parallel Power Supplies Can Fight Each Other (

[@sincerelyyours7538]

I would put a big honking diode in series with each positive lead so one power supply can't backfeed the other if the voltage of one sags during use. You'll lose 0.7 volts forward drop on each silicon diode and at 40 amps that is 28 watts per diode so they would need to be heatsinked and force-air cooled. Or try using a surplus server power supply. Many of those can supply 12 volts at 75 to 100 amps depending on input voltage.

[@justinmaas5834]

Astron 70 amp supplies are designed to do this. They have a lug on the back to interconnect them.

[@jimlosh3305]

If you would like to try putting 2 PS in parallel, you can try putting a fifty amp fuses in each dc line. They will act as a low resistance link and give a bit of a volt drop so the supply don’t fight each other. I have done this before and it seems to work well.

[@davep6977]

A fuse isn't supposed to have resistance

[@jimlosh3305]

Incorrect, If a fuse was not resistive it would not work. Refer to Ohms law.@@davep6977

[@kaoti]

​@@davep6977 yet it still does... a minute amount, but idk worst case scenario is you blow the fuses and one of the supplies...

[@ButtonsKing]

3:30 Diodes are probably even safer, but you will lose 0,7V. The diodes must be rated for the continuous current and cooled properly (0,7 V x 50 A = 35 W of heat).

[@paulshockieuk2651]

Could a voltage rectifier put inline work to stop extra volts going into the other power supply

[@robertmeyer4744]

very good. Parelle power supplies is tricky. with Astron 50 amp no so hard. have to pend them. their is a voltage adjustment on fixed models. set both to same voltage with in .1V or better. then use equal length of #6 AWG wire or bigger copper wire to a busbar for pos and neg. also use amp meter to check each supply for even current draw. it is a lot of work . Astron uses a LM 723 Reg IC and you can strap them together to track the same but that even more work. now on SMPS supply's like mean well or some mega watt they have a link cable to put them together for more amps. with all that it is much better just get a bigger amp supply. 75 amp to 100 amp will be just fine. best to run 2 sets of 6AWG welding cable. this will be easy to move around. 73's

[@michaeledmonds3027]

Congratulations on becoming a "thousandaire", Dave! Best of health to you.... Michael

[@loretti1039]

Congrats on the 1000th episode !

[@mikebavoso26]

Hi Dave, I was running a Henry 1200 watt moble RF amp at home. I used two Astron 75 amp power suppies which has a additioal terminal on each 75 amp power supplies just for the purpose of connenting two supplies. Worked fine for years until the burned down. Not due to the power supplies.

[@naman2000]

Congrats on 1000!

[@UDX4570PalmSprings-yh1mv]

The only reason why I shy away from transistorized amps in a base station configuration is they require a ungodly amount of amperage to operate them. Great video none the less!

[@LeeMcc_KI5YPR]

Good video. As Dave said, the term is control loop. Some supplies are designed to be paralleled with no additional circuitry. They will have a separate voltage sense input, so the supply regulates the voltage at the load rather than the supply. This is common in servers which have redundant supplies. Some consumer supplies do this as well, as mentioned in the comments. Only in a pinch should you use a big fuse or power resistor(s). Dave is absolutely correct. For a new install, just get the big supply.

[@n0vty873]

I have been running dual switching power supplies for years with no problems.

[@davep6977]

I have the same amp which I bought doa and rebuilt it. One thing to consider is your operating mode. SSB is a 20% duty cycle as opposed to AM. I have a Astron 60 amp and it works fine at 14.5 volts (they are adjustable internally) I would run it higher but TE Systems don't recommend that when you use the rf keying.

[@jimlanigan.wa3erq341]

Great advice Dave

[@dennisjones8991]

The best way is to use a power supply that will supply 125 % of the required current. If you must use two power supplies, use two that match in current output that together can supply 125% of the required current. You can use power supplies that have different current ratings in an emergency situation. The best way in either case of using multiple power supplies involves modification of the voltage control circuit with a multi turn pot for voltage trim. Using a pot that has 10 turns rather than a less than single turn has the advantage of dialing in the voltage to almost 3 digits to the right of the decimal point, such as 13.803 volts. In this way you can dial in the control circuit for BOTH power supplies to09 the voltage which must match on each power supply using a quality solid state voltmeter with resolution down to ??.???. This works for any variable output power supply including those that can change the voltage internally, which is safer as no fingers, yours or others, can change the voltage accidentally. 73 N7TZQ

[@jamesmoore6424]

Great work on the 1000th episode. I have done a poor man's supply for my approx 500 watt transitory amp. What I did as I am not well funded, is scored a 100 Ah lifepo. This is charged by both poker and solar. The main thing is that it is usually charged. If we have an emergency situation at home I can easily, connect everything to the battery and run qrp. It is a similar setup to what I had in my flat 30 odd years ago running my old CB. Except there was no solar then. I could get a few more batteries an become totally solar. But my health is unfortunately ler me down... the project has stopped with a fan dipole lying on my roof. And all the bits for my end feds still packed up. At least I have my 6btv.

[@glenmartin2437]

Thank you, Dave. N0QFT

[@wolson9]

Congratulations on your 1000 th! You have greatly helped hams everywhere, including me. AI7MY