LM, LMA, LM, LM, LM SNOSBT0L –FEBRUARY – REVISED SEPTEMBER LM, LMA and LM Family Wide VIN. LM 3-terminal 1A Positive Voltage Regulator DESCRIPTION. The UTC LM78XX family is monolithic fixed voltage regulator integrated circuit. They are. LM Positive +15v Voltage Regulator. LM Positive +15v Voltage Regulator. Price: $ Datasheet: application/pdf icon LMpdf. LM + 15v.
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Project came out great and is still running strong. I need one that is rated for 40VDC or higher. It makes the 24V regulator work harder but gets around ln7815 immediate problem. Register now while it’s still free! They do not get hot. By joining you are opting in to receive e-mail.
LM7815 Positive +15v Voltage Regulator
I think you’re SOL. The Architecture, Engineering and Construction AEC industry is constantly looking for process improvements to better manage potential project delays and costs.
The transformer we’re using outputs roughly VDC unfiltered which gets sent into a lm regulator to make the 15V output, we can’t use a transformer with lower output because we need the higher voltage to feed the buck regulator which outputs 24V. Are you avoiding the switcher due to noise?
I can do absolutely anything. Resources Few production environments have the luxury of ordering new equipment to replace existing machines on their shop floor. There is a homework forum hosted by engineering.
A string of 1Nx can also be used. That will remove voltage that would otherwise be ‘seen’ be the regulator. The circuit draws mA at max load. The TL runs out-of-regulation sometimes lm7851 insufficient input to output headroom when the 28V input is at absolute minimun but it has done the job for several years in a product. Otherwise, use a zener as suggested, or even put another with a 15V zener in the ground leg makes for om7815 30 volt regulator ahead l,7815 the for the 15V.
I had a similar situation for a simple low current supply running from 28VDC down to 12 V which needed to withstand 2 msec transients up to 88V, so I just put a TL V rating regulating down to 24 volts, and then a Close this window and log in.
Current requirements aren’t too high, mA would probably suffice. No doubt you would need some resistors in series to balance the Voltage.
I’ll have to check to see if we can run the 24V buck into the 15V reg. Now I’m currently in the process of probing the board and trying to catch any issue that may be caused by the switching transients on the l7m815 rails. I would just run the off the output of the buck.
LM / L / – Retroamplis
I have saved my bacon from being fried by using a power zener in series with the input. With that much drop and assuming more than a few tens of milliamps in currentI would use a buck converter pm7815 save a ton of power. Can ln7815 feed the 15v and 5V regulators from the 24V regulator output? Hi roydm; a missed point here by a lot of folks was “drop-in replacement so no board cycle would be needed”.
So far all I could find is the Fairchild KA78T15 regulator, which WOULD be perfect, however from what I’ve been able pm7815 tell its an obsolete part and only Rochester Electronics is selling those parts and this board is expected to last 10 years, so we don’t want to be limited to one supplier.
We may be able to use a 3 pin buck regulator chip, provided it has a reasonably clean output.
Click Here to join Eng-Tips and talk with other members! It’s easy to join and it’s free. We shall find out tomorrow! Also I tested a few of our zener’s in stock and the best onewe had was only 1. Does anyone know of a 15V fixed output 3 terminal regulator that can handle up to 40V or more input voltage, preferably in the to package? Keith Cress kcress – http: Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.
Not very elegant but it works and it moves the problem from finding exotic 40 V parts to handling the heat produced in the zener. I’ll be taking a better look at the switching transients on the rails tomorrow to see if they’re causing me any issues. Best bet is the LM You don’t need a heatsink and they are fully protected, so even if you short the output they won’t burn up.