Help with finding replacement for voltage "Dropper Type"

[hoyahelper]

Hey all,

I've attached a datasheet for what seems to me like a 5 pin voltage regulator - with 5v output - i can't get this specific one anymore but am assuming theres gonna be a modern replacement but i haven't had much experience in this field and was wondering if someone could guide me!

Thank you lots!

 

[Khron]

How about a 7805 (and bend the pins if necessary)?

What's the voltage going into this? (To determine whether it really needs to be a low-dropout regulator or not)

 

[hoyahelper]

How about a 7805 (and bend the pins if necessary)?

What's the voltage going into this? (To determine whether it really needs to be a low-dropout regulator or not)

Can you get 7805s in 5 pin configurations? Voltage in is 25v so it could be possible?

 

[Khron]

Why 5 pins? 7805's should take up to 35v in; any idea what sort of current it would need to provide?

 

[JohnRoberts]

How much current do you need?

JR

 

[hoyahelper]

Why 5 pins? 7805's should take up to 35v in; any idea what sort of current it would need to provide?

its 5v out - actually 15v in so no issue there - current is 2a out

extra 2 pins are shown in use on this schematic - pretty sure they are essential right?

its the str9005

 

[danfrank]

You need to check the power dissipation that the regulator you're going to use, has. If you're dropping 15 volts in to 5 volts out at 2 amps, that is a 20watt dissipation that the regulator has to dissipate.
The LM323 will do the job but it costs $67 at mouser, you used to get them for $1 as new surplus!
Another regulator that would work is the LM338 which is good for 5 amps but it is adjustable output so you will have to set the output voltage. Either way, you're going to need a large heatsink to dissipate that kind of power from the voltage drop the regulator has to do.

 

[Walrus]

Schematic shown say 7.5 volts in, not 15!