Stopid basic electronics question

[borgqueenx]

Heya people long time no see
i have a break in the laserworld because i have my laser projector but im keeping making shows for it that i later need to edit once my projector is finished so i kinda quit on my laser hobby and start picking it up again once i have some money...

So here is a stopid question:
I have a Flexdrive p3 or something that requires 5-12v and i think 1A, to analog feed my 445nm diode. I have a in plastic covered converter in my projector, wich makes it possible to feed the flexdrive with that. its not mountable to the baseplate so it lies loose covered in plastic so it doesnt make contact. (converter=psu wich converts 220v into 5v)
Now im getting a new laser module including driver soon, and i can choose a new PSU/converter for it as well...

My question is, can i get rid of that stopid plastic covered converter, and use the PSU that i can order with my new green laser? it gives out 5V, but also gives 16A instead of 1A. is that dangerous, will it harm equipment that uses 1A? or can those parts simply draw what they need?
if possible i want that 16A device because it can then on the end feed all my laser drivers. Right now i have 2 converters and i would like to make it one.

Thanks

 

[bennett326]

I think yes but. But I would let someone else confirm to
The flexmod is linear so with that current your just gonna have a lot of heat ....right?

 

[Cyparagon]

5V is not enough to run a blue diode. You need at least 6-7V.

 

[Elektrotechniker]

The devices should draw as much current as they need, as long as the psu can deliver it. At least that's what happens with all my power supplies.

 

[borgqueenx]

The devices should draw as much current as they need, as long as the psu can deliver it. At least that's what happens with all my power supplies.

thanks

and @Cyparagon: 5v. running well....a 700mW 445nm Diode.

someone can confirm that electronic stuff just takes as much amperages as nessacary? they cant be "overfed"?

 

[Jacob32123]

It will only take however much current it needs. That is correct

 

[Cyparagon]

It is no longer regulated! I needs a drop of >1.5V to work properly. If you only give it .5-1V, it will not give the diode the current it is supposed to. You can turn the current UP until the current READS 700mA, but it is actually SET to a much higher current. If for any reason your power supply decides to move up to 5.2V, you're fcked.

The output also won't be nearly as linearly proportional to the input signal.

 

[borgqueenx]

It is no longer regulated! I needs a drop of >1.5V to work properly. If you only give it .5-1V, it will not give the diode the current it is supposed to. You can turn the current UP until the current READS 700mA, but it is actually SET to a much higher current. If for any reason your power supply decides to move up to 5.2V, you're fcked.

The output also won't be nearly as linearly proportional to the input signal.

I dont understand alot of electronic talk im afraid
Look at this: http://hacylon.case.edu/ebay/laser_diode/FlexModP3.php

Clearly shows it needs 5v... If feeded more then 5v it will be transferred into heat...this is what feeds my 445nm diode.

So you wouldnt recommend using the new psu? It will blow the diode or/and driver?

 

[Cyparagon]

"Power input: 5-24VDC"
"Max Output (Diode) Voltage: Vdd - 1.5"

You're feeding it 5V. Therefore, max output diode voltage is theoretically 3.5V

Get a 7V supply or greater.

edit: I'll try to dumb it down...

Lets just say for the sake of argument you have a regular current regulator (like the lm317 for example) that has a minimum voltage drop of 2V, and your diode has a forward voltage of 5V, and you're powering it with 2 lithium cells. What happens as the batteries drain? 8.4V: regulated. 8V: regulated. 7V: regulated. But what happens at 6.9V? The current starts dropping. Lets say by the time it hits 6.5V, the current is only half what it should be. Lets say you notice this and turn up the pot to bring the current up. Everything's fine, right? WRONG. What happens when you put fresh batteries in? BOOM.

The same thing is going on with your setup. The current you have it set at isn't 700mA, it's who-knows-how-much-higher. Could be 3A. The regulator doesn't have enough voltage to supply the 3A though, it can only supply 700mA. But if you raise the voltage, even a little, the driver will try to use that voltage to push more current through the diode. That means it is not regulated.

 

[borgqueenx]

"Power input: 5-24VDC"
"Max Output (Diode) Voltage: Vdd - 1.5"

You're feeding it 5V. Therefore, max output diode voltage is theoretically 3.5V

Get a 7V supply or greater.

edit: I'll try to dumb it down...

Lets just say for the sake of argument you have a regular current regulator (like the lm317 for example) that has a minimum voltage drop of 2V, and your diode has a forward voltage of 5V, and you're powering it with 2 lithium cells. What happens as the batteries drain? 8.4V: regulated. 8V: regulated. 7V: regulated. But what happens at 6.9V? The current starts dropping. Lets say by the time it hits 6.5V, the current is only half what it should be. Lets say you notice this and turn up the pot to bring the current up. Everything's fine, right? WRONG. What happens when you put fresh batteries in? BOOM.

The same thing is going on with your setup. The current you have it set at isn't 700mA, it's who-knows-how-much-higher. Could be 3A. The regulator doesn't have enough voltage to supply the 3A though, it can only supply 700mA. But if you raise the voltage, even a little, the driver will try to use that voltage to push more current through the diode. That means it is not regulated.

Ah okay thanks
Now i understand
Il just turn down the laser to 1mw and then connect the new supply.

EDIT: thanks worked great although i dont see any differences. (that plastic covered converter can be set to different voltages.)
its now running at a steady 7.52V, according to my multimeter. thats okay right?

 

[Flaminpyro]

Is that 7.52 volts while the laser is running or while there is NO load on the converter ?

Ah okay thanks
Now i understand
Il just turn down the laser to 1mw and then connect the new supply.

EDIT: thanks worked great although i dont see any differences. (that plastic covered converter can be set to different voltages.)
its now running at a steady 7.52V, according to my multimeter. thats okay right?

 

[borgqueenx]

Is that 7.52 volts while the laser is running or while there is NO load on the converter ?

when the laser was not running. just measured the wires coming from the converter, while the wires were disconnected from the flexmod.

ofcource i have set the flexmod gain down for quite a bit to get ~700mW again. else i would have 3000mW if i understand correcly and after 1 second 0mW.
and have altered my lasershow software to match the analog signal again so it will be normally regulated.

 

[Cyparagon]

Is this 7.5V supply capable of 1A or more?

 

[borgqueenx]

Is this 7.5V supply capable of 1A or more?

i think it feeds maximum 1A. i dont think it can supply more. basicly its a outlet universal charging adapter broken open en put the board of it inside my projector.
but the 445nm if running fine now on 7.52v. but nothing changed since 5v. it simply doesnt need adjusted settings in my laser software anymore to get fade ins and fade outs.

 

[borgqueenx]

Someone at work told me that a tv wich used 12v and 5a, is fed with 12v and 6a it could die.
is this true? Then i shouldnt use a 17a psu on a laser wich only needs 1a? (Wich is at the beginning because later i will connect more lasers to the psu)

Im really confused now. Devices / lasers only draw amperage on what they need? Ive heard giving more voltage is not healthy but never heard of amperage being dangerous...

 

[borgqueenx]

someone?