go_away

Author Topic: 12volt FM or AM transmitter + Stepping 12v down to ~5v?  (Read 4229 times)

0 Members and 1 Guest are viewing this topic.

Offline HDL_CinC_DragonTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,261
  • Helpful? 5
12volt FM or AM transmitter + Stepping 12v down to ~5v?
« on: December 06, 2007, 07:47:57 PM »
I tried googling on how to make a 12 volt FM transmitter but all I got were websites selling pre-made ones for as low as like 30 bucks or something like that. Does anyone know of a deent tutorial or at least a circuit diagram of how to make a simple xmitter?

I recently saw this one linked on the forums:
Link
But it uses at most 3 volts. If I used a resistor or a vreg to drop 12v down to ~2v, the heat would be ridiculous right? Not to mention horribly inefficient?
« Last Edit: January 12, 2008, 12:22:01 PM by HDL_CinC_Dragon »
United States Marine Corps
Infantry
Returns to society: 2014JAN11

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: 12volt FM or AM transmitter - couldnt find one using google?
« Reply #1 on: December 06, 2007, 08:12:13 PM »
switching regulator

you can get them as free samples
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline HDL_CinC_DragonTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,261
  • Helpful? 5
Re: 12volt FM or AM transmitter - couldnt find one using google?
« Reply #2 on: December 06, 2007, 08:23:02 PM »
are they better than standard vregs/resistors? how efficient are they?
would this be a good option to use for that circuit to step 12v down to "2.6v"?
United States Marine Corps
Infantry
Returns to society: 2014JAN11

Offline JonHylands

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 562
  • Helpful? 3
  • Robot Builder/ Software Developer
Re: 12volt FM or AM transmitter - couldnt find one using google?
« Reply #3 on: December 06, 2007, 09:30:32 PM »

Offline HDL_CinC_DragonTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,261
  • Helpful? 5
Re: 12volt FM or AM transmitter - couldnt find one using google?
« Reply #4 on: January 12, 2008, 12:20:55 PM »
Thanks for the reference on that Jon. I would be very active in trying to get a hold of one of those if it wasnt so expensive >_< I doubt these things can be obtained as samples since theyre so expensive huh? And im also assuming that just using some resistors in series to step down the voltage would be a bad idea right? Since they dont regulate anything, if I was getting 18volts as input and expecting only 12, I would fry my circuit... damn I hate money restrictions lol
« Last Edit: January 12, 2008, 12:22:26 PM by HDL_CinC_Dragon »
United States Marine Corps
Infantry
Returns to society: 2014JAN11

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #5 on: January 12, 2008, 01:49:42 PM »
that thing is expensive since it's a pc board with all the plugs and stuff

looks around here
http://para.maxim-ic.com/cache/en/results/4632.html
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline paulstreats

  • Supreme Robot
  • *****
  • Posts: 1,381
  • Helpful? 21
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #6 on: January 12, 2008, 02:57:52 PM »
if youre not stepping down too much you can use resistors or pots.

e.g.

i have a camera module that operates on 3 volts, but only have a 3.3v regulator. So i use the regulator as normal to provide 3.3v and then from that have a pot connected to a resistor connected to gnd. If i add a connection between the pot and the resistor i get a new voltage level depending on how i set the pot
note: this is okay for small shifts or steps down, but i wouldnt recommend it for a massive step

Offline HDL_CinC_DragonTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,261
  • Helpful? 5
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #7 on: January 13, 2008, 11:22:55 PM »
12v to 5v is a relatively large shift is it not? I mean 7 wasted volts is pretty significant... plus I would like to use some kind of regulator like the switching ones so that im getting a constant ~5v instead of my output voltage slowly going down with my source voltage from the battery... would it be difficult/expensive to just make my own little switching regulator? Size wouldnt really be a factor of concern for me.
United States Marine Corps
Infantry
Returns to society: 2014JAN11

Offline paulstreats

  • Supreme Robot
  • *****
  • Posts: 1,381
  • Helpful? 21
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #8 on: January 14, 2008, 01:19:39 AM »
Have a search for a 'buck' circuit, there are two types, one that increases voltage and one that decreases it. (these are essentially what a switching regulator is)

They usually comprise of either  capacitors(up to 98 percent efficient) or inductor(~83percent efficient) plus a couple of transistors or mosfets.

Its more likely to cost about the same as just buying one unless you already have the components going spare

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #9 on: January 14, 2008, 08:37:22 AM »
or getting a free sample
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline HDL_CinC_DragonTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,261
  • Helpful? 5
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #10 on: January 14, 2008, 09:02:57 PM »
@paul
I googled "buck step down circuit" but all I could find were circuits with inductors in them and I would very much like to go with maximum efficiency.

@ed
Any idea from where I can get one as a sample?
United States Marine Corps
Infantry
Returns to society: 2014JAN11

Offline SmAsH

  • Supreme Robot
  • *****
  • Posts: 3,959
  • Helpful? 75
  • SoR's Locale Electronics Nut.
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #11 on: January 14, 2008, 09:16:24 PM »
yea theres tones of sites that are willing to give you a free sample i've gotten heaps of them by advertising their names on my robots at comps...
Howdy

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #12 on: January 14, 2008, 09:23:26 PM »
i postd it in a thread named "12volt FM or AM transmitter + Stepping 12v down to ~5v?"

here it is
http://www.societyofrobots.com/robotforum/index.php?topic=2554.msg20004#msg20004



« Last Edit: January 14, 2008, 09:24:08 PM by ed1380 »
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline HDL_CinC_DragonTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,261
  • Helpful? 5
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #13 on: January 14, 2008, 09:40:42 PM »
Yeah I went to that link and stayed at it for quite a while too. I didnt see a sample button... until now >_< sorry ed!


Any model number in particular that you would suggest or should I search around some more on there? I narrowed my search down to 10 different models: Link



My only qualms about those devices is that theyre all SMD devices. I need ones that have the pins like this one.
« Last Edit: January 14, 2008, 10:04:10 PM by HDL_CinC_Dragon »
United States Marine Corps
Infantry
Returns to society: 2014JAN11

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #14 on: January 15, 2008, 05:35:07 PM »
under packaging it'll tell if it's smd of through hole etc

the sot and sop ones are smd w/ legs.  you might be able to bend them out.



I'll look at teh part # of teh regulators i have since they're DIP and see if they're still available
« Last Edit: January 15, 2008, 05:36:08 PM by ed1380 »
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #15 on: January 15, 2008, 05:41:12 PM »
look around here
http://www.allegromicro.com/en/Products/Categories/Sanken/index.asp

i have the 8050jd. the 8050jf is what you might want
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline dunk

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 1,086
  • Helpful? 21
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #16 on: January 15, 2008, 08:14:47 PM »
i've used the LM2596 switching regulator quite a lot.
it's available in SMT or through hole versions. rated up to 3A.

if you plan on drawing a constant 3A from it i recommend using the through hole version because even though it's a switching regulator it still generates a bit of heat. at those sorts of loads you have to bolt it so something metal.

you need a few other components to make it work. all detailed in the datasheet.
probably the toughest thing about it is finding a shotkey diode capable of handling the return current but i've successfully used several 1A shotkeys in parallel in the past.

you can see it in use on the schematic here: http://www.societyofrobots.com/member_tutorials/node/25

dunk.

Offline HDL_CinC_DragonTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,261
  • Helpful? 5
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #17 on: January 15, 2008, 08:43:24 PM »
cool, thanks ed :) I just requested a sample of the JF. I owe you :) hopefully theyll get approved :)
United States Marine Corps
Infantry
Returns to society: 2014JAN11

Offline HDL_CinC_DragonTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,261
  • Helpful? 5
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #18 on: January 20, 2008, 12:18:29 AM »
I just got my Switching Regulators (I asked for 2 and got both of them :))
They dont fit in my breadboard though >_< so im either going to risk bending them to make them fit or im going to make a socket translator
United States Marine Corps
Infantry
Returns to society: 2014JAN11

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #19 on: January 20, 2008, 10:01:15 AM »
what about getting some single strand wire. solder like 1" to each pin and then bend that as necesary for it to fit
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline HDL_CinC_DragonTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,261
  • Helpful? 5
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #20 on: January 20, 2008, 11:06:53 AM »
... darn it ed, stop being so friggen brain using! You make my brain feel sad!
:P

Thanks for the tip ed, im gunna do that :)
United States Marine Corps
Infantry
Returns to society: 2014JAN11

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #21 on: January 20, 2008, 01:44:26 PM »
brain using? lol.

it's my ghetto self
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline Steel_monkey

  • Full Member
  • ***
  • Posts: 85
  • Helpful? 0
Re: 12volt FM or AM transmitter + Stepping 12v down to ~5v?
« Reply #22 on: January 20, 2008, 04:38:43 PM »
It looks like many questions are asked for many times again and again. What about creating "suspended" topic about voltage transformation with few important posts? I have this wonderful link: http://www.nomad.ee/micros/mc34063a/  ( as I know, L max should also be calculated, so it must be taken in account).  Also linear regs require some info to be mentioned.
« Last Edit: January 20, 2008, 04:41:34 PM by Steel_monkey »

 


Get Your Ad Here