really...
I had better results with NTE parts than I did with digikey... maybe I went for the too cheap versions on digikey...

NTE and Digikey don't manufacture parts, they buy from companies that do. Both have too much to lose by buying "cheap" parts that may be rejects or counterfeit. Buy new from recognizable brands (TI, On Semi), or NOS (New Old Stock) parts from Nat Semi, Fairchild, Motorola, etc from reputable sources.

 

Digikey are purely a supplier, NTE rebrand other companies components with their trade mark.
NTE equivalents typically cost >3 x other makes.
I stay away from them unless I absolutely have no choice.
Max.

 

well,
In the future I will ask... I am going to make a list of parts that I need for the DC power supply...And did You look at the schematic I sent you...
I found something in the textbooks that made me smile...its in the

http://www.allaboutcircuits.com/textbook/direct-current/chpt-3/safe-meter-usage/

Safe Meter Usage
Chapter 3 - Electrical Safety

and states...


" All good-quality multimeters contain fuses inside that are engineered to “blow” in the event of excessive current through them, such as in the case illustrated in the last image. Like all overcurrent protection devices, these fuses are primarily designed to protect the equipment (in this case, the meter itself) from excessive damage, and only secondarily to protect the user from harm. "

All the best
btw... how long does these posts go on... ( meaning if we stop texting do they close them down...?)

 

well,
In the future I will ask... I am going to make a list of parts that I need for the DC power supply...

I use Digikey to find the maximum I should pay for a part, excepting anything branded NTE. If you have a local electronics surplus store, you may be able to find some decent prices. Otherwise, I'd go with Mouser, Jameco, or similar.

And did You look at the schematic I sent you...

Looks like an example from the datasheet. Not very interesting without component values. Would be easier to read if it was on one page; you can set an option in Eagle to fit to one page regardless of the scale you select.

Like all overcurrent protection devices, these fuses are primarily designed to protect the equipment (in this case, the meter itself) from excessive damage, and only secondarily to protect the user from harm.

IMO fuses do not protect equipment or components; they prevent fires.

 

There are many kinds/types of fuses, fast blow, slow blow, semiconductor fuse, the latter protects solid state equipment with very fast sweep through or very hi speed operation.
Max.

 

sorry...I haven't had much time to do electronics while my wife is in the hospital...

 

sorry...I haven't had much time to do electronics while my wife is in the hospital...

Your Wife's (and your) health are more important than working on electronics projects and/or responding to posts on this forum...

 

Your Wife's (and your) health are more important than working on electronics projects and/or responding to posts on this forum...

Thank you very much...

I have been looking into electronics whilest running around tho...

And I am very curious about transistors... I know that arduinos are " in " now... but my question is this. Why can a Mosfet and an arduino be compatible with different voltages but not a 555...

http://blog.lib.umn.edu/ali/2010ema8600/tutorials/

In the tutorial its using a arduino and a different voltage in the mosfet to run a load... couldn't I use a mosfet the same as in the tutorial and run a 555...
why can't I run a 555 with a 9 volt battery and hook up a BDX53c and hook it up to a 12 volt car battery and run a 9 amp DC motor with it

that baffles me...

All the best

 

In the tutorial its using a arduino and a different voltage in the mosfet to run a load... couldn't I use a mosfet the same as in the tutorial and run a 555...
why can't I run a 555 with a 9 volt battery and hook up a BDX53c and hook it up to a 12 volt car battery and run a 9 amp DC motor with it

You can. With a MOSFET, you just need to make sure that there's sufficient gate voltage to turn it on fully (for low Rds(on)). For a transistor, you just need to provide sufficient base drive current for it to saturate. If you want to control motor speed, you'd operate the MOSFET or transistor in their linear region.

BTW, since this is a new topic, you should start a new thread...

 

BTW, since this is a new topic, you should start a new thread...

I would like to...but I don't know ( I guess I should know ) how... Is it a problem to start a new topic when I haven't finished with the old one...

Cheers

 

The topic discussed in the post should match the title and the title should be descriptive (not like a recent "Urgent Need Help" post - people who need urgent unspecified help should go elsewhere...). An appropriate topic allows users decide if they're interested or skip it if they're not. This is now more important because the new forum doesn't show the first part of the original post text if you hover over the title. And it no longer shows you how many pages of posts there are so you can skip the first page; important if you have a slow connection.

EDIT: forgot to mention that the "Post New Thread" button is near the bottom of the main forum page.

 

If you want to control motor speed, you'd operate the MOSFET or transistor in their linear region.

In the collector emitter region and the equivalent in the mosfets...
So the 9 volt fed into the 555 leading into the transistor base... is not effected by the 12 volt battery source in the collector emitter ( linear ) region.........................................that's very interesting not to mention " kewl ".

All the Best

 

BTW, since this is a new topic, you should start a new thread...

Thanx for clarifying that question and showing how not to hijack my own thread....

Getting back to power supplies...

Thinking out loud again...
I would imagine two power supplies. One that has the capabilities that the LM317 provide... Plus one that powers 6 - 12 volts with a lot more amperage... say 10 - 15 amps ( is that too much amperage )

Cheers

 

There are many kinds/types of fuses, fast blow, slow blow, semiconductor fuse, the latter protects solid state equipment with very fast sweep through or very hi speed operation.
Max.

After dealing with an exploding 555 against a 12 dc lawnmower battery I'm interested in the Hi speed operation ...
I am reminded a few years back I accidently touched a screw driver against a 3 marine battery house connection and watched the heavy duty screw driver glow in seconds and also noticing my wedding ring in the hand that was holding the screw driver.........

Cheers

 

I would imagine two power supplies. One that has the capabilities that the LM317 provide... Plus one that powers 6 - 12 volts with a lot more amperage... say 10 - 15 amps ( is that too much amperage )

For multiple voltages, you could build a power supply with 2 or more independent regulators.

Regarding current, what types of projects do you envision? I have found that a few amps is sufficient for most things I work on. But I do have half a dozen power supplies for cases where I need more current or higher voltages...

 

Regarding current, what types of projects do you envision?

I would at least like to go the full range of a 2N3055...

Cheers

PS I like the idea of two independent ranges...

 

Regarding current, what types of projects do you envision? I have found that a few amps is sufficient for most things I work on. But I do have half a dozen power supplies for cases where I need more current or higher voltages...

What size box would I need to contain all the electronics in... any susgestions

 

What size box would I need to contain all the electronics in... any susgestions

Minimum enclosure size will depend on the size of the components you use; in particular, the transformer. A transformer that deliver around 10A net will be large.

 

Minimum enclosure size will depend on the size of the components you use; in particular, the transformer. A transformer that deliver around 10A net will be large.

31 August 15

Sorry,
Many issues to deal with...

haven't lost interest in electronics...just too much on my plate.

RandyFL