Voltage Drop (USB and "other") under load - How do we eliminate it?

[SurvivorMcGyver]

To bad You can't edit the header of a new forum post.

Anyways -- no need to read futher. I found my problem. It was in my test set-up. The pressure of the atty thread on the adapter (when assembled - ONLY) was causing a minor short that dropped the voltage.

Anyways, good luck and happy vapping and modding all -- sorry to distract


I won't go in to all the details, as there are many, Sooo....I'll pose the simple question --

Has anyone learned what it takes to eliminate the voltage drop under load?

I haven't investigated ALL the regulators, power suplies. etc., etc., on the market but there MUST be something out there that has a stable output when "set" - then placed under load -- even a friggen regulated 'puter power supply drops around a volt (or more) under load at both 12v AND 5v -- egads -- poor hardrive (S) (and all else that depend on it LOL)

I set most all of my prototypes at a simulated load before implementing them into the finished device (except, of course, my variable units). This works fine BUT.........

Is PWM the awswer? With current control?

Or what?

I suppose the latter (current control is the answer) But I'd like anybody's reputable input that is willing to offer it.

Thanks

 

[bobtow]

I won't go in to all the details, as there are many, Sooo....I'll pose the simple question --

Has anyone learned what it takes to eliminate the voltage drop under load?

I haven't investigated ALL the regulators, power suplies. etc., etc., on the market but there MUST be something out there that has a stable output when "set" - then placed under load -- even a friggen regulated 'puter power supply drops around a volt (or more) under load at both 12v AND 5v -- egads -- poor hardrive (S) (and all else that depend on it LOL)

I set most all of my prototypes at a simulated load before implementing them into the finished device (except, of course, my variable units). This works fine BUT.........

Is PWM the awswer? With current control?

Or what?

I suppose the latter (current control is the answer) But I'd like anybody's reputable input that is willing to offer it.

Thanks

Have you thought of connecting your bypass to a small ac/dc power supply?

 

[SurvivorMcGyver]

Nope... but I have an 800 watt unit sitting right here.......

[Edit] Ooops that's a DC to AC unit....

Besides, I'd like it portable

 

[Nuck]

You need 2.4 amp output to handle a 510 at 5v. Anything less and you will experience voltage drop. The only way to get it with a USB connector is going to be an AC power source. I've never seen a portable battery pack that can output that much current.

 

[SurvivorMcGyver]

You need 2.4 amp output to handle a 510 at 5v. Anything less and you will experience voltage drop. The only way to get it with a USB connector is going to be an AC power source. I've never seen a portable battery pack that can output that much current.

I STILL get a voltage drop under load hooked straight to a 15A 5V DC power supply.

Perhaps it is the way I'm "testing under load" or the way I'm testing?

I am measuring both straight off the main buss as well as just before the atty two different meters simultaniously.

 

[SurvivorMcGyver]

3.36 volts - 1.52 Amps (peak), 5.1 watts (peak), 2.3 Ohms 510 atty off a 15A 5 volt buss. I'll get the same thing off the 12V buss with a 25W switching regulator set at 5V out -- the list goes on....

Now back to the original question: How does one illiminate it (Voltage drop under load {with an ampul power source})?

Is PWM the awswer? With current control?

Or what?

 

[BuzzKill]

your testing must be screwy , a regulated supply should not drop in voltage , you might have a bad connection , use a knife and pull the center of the atty conn. out a bit and clean all connections .

A computer power supply rating is distributed across all the available voltages , read the specs for the 5volt output it is not very high !

 

[WillyB]

3.36 volts - 1.52 Amps (peak), 5.1 watts (peak), 2.3 Ohms 510 atty off a 15A 5 volt buss. I'll get the same thing off the 12V buss with a 25W switching regulator set at 5V out -- the list goes on....

Now back to the original question: How does one illiminate it (Voltage drop under load {with an ampul power source})?

Is PWM the awswer? With current control?

Or what?

You got something jacked up. I got a 5.1V@2A 2WIRE modem PS hard wired right to an atty/switch. My cheap meter reads about 4.7V when I hit the button with a Joye atty. Which sounds about right for 2A.

 

[DVap]

I've been thinking about the whole voltage drop under load issue for awhile now... thanks for the topic!

Without researching, and if my memory serves, I can set up for constant current simply by using an LM317 regulator with a trim-pot... but I think it tops out around 1.5amps (even with a heat sink).. and you still need a battery/supply that can deliver that kind of current over the life of the charge.

Any linear regulators out there good for the 2.5 - 3 amp range? I've not worked with these in about 5 years or more, so I could be behind the times.

 

[SurvivorMcGyver]

Switching regulators with a feedback loop are pretty nice at producing consistant voltages (still loose about .5v due to overhead) - my challenge now is controlling the wattage at the varying voltage of batteries -- it's beyound me. Guess I need to pull out the ole flux capasitor LOL -- although, I am eyeing some supper capasitors tho......

 

[mnealtx]

You could have voltage sag due to wiring, as well - use the heaviest guage wire you can get away with. I have a usb-based passthrough that runs off an a/c adapter and have to set the wallwart at 6v to get 5v under load.