Recent content by oscarcot

  1. O

    LM338/LM318 Not enough power. Vref drops!

    Hurray. The problem of the 6 burnt LM338 is solved. I bought one from a different store and soldered it into the very same circuit board where I had the others, and it wasn't damaged at all! I conclude, all the LM338's from that store were defective. ------------- I guess, now that we got...
  2. O

    LM338/LM318 Not enough power. Vref drops!

    Wow, audioguru. I really apreciate the patience you have to try to help me out. Thanks a lot. Ok, first of all, sorry for my lack of vocabulary (not a native english speaker). I think the thin film of thermal grease you say is the "plastic cover" I was talking about. I'll attach some pictures...
  3. O

    LM338/LM318 Not enough power. Vref drops!

    Hi. Well, well, well.... This is what happened now: 1. I got 2 LM338 IC's with the T-03 encapsulate and a heatsink. I connected them to the circuit. (The Vout wasn't in direct contact to the heatsink, it had a plastic cover.) The servo moved alright (without stalling), drawing a current of...
  4. O

    LM338/LM318 Not enough power. Vref drops!

    Ok. Now I've got 2 replacements and a heatsink. If everything else was alright, I think it must work now already. I'll tell you later when I connect them.
  5. O

    LM338/LM318 Not enough power. Vref drops!

    Agree. Yeah, that's exactly what I want. I stall it on purpose to make it drain more current to see if the regulator works properly providing it 5 Amps. I'm measuring it with my ampmeter in series with the battery but current level only reaches 1.33 Amp when stalled. Unfortunately, to do that...
  6. O

    LM338/LM318 Not enough power. Vref drops!

    Haha. Ok, sorry. Well, yeah... maybe it's dissipating a little too much power but I just leave it that way for about 3 or 4 seconds when I'm stopping the servo. I swear it has always been cool enough to put my fingers over it without getting them burnt. But anyway, I'm buying a new LM338...
  7. O

    LM338/LM318 Not enough power. Vref drops!

    By the way... I forgot something. The servo does move freely and happily, but when I try to stop it is when the voltage drop ocurrs. And by the way!... output voltage has really big fluctuations when the servo is moving freely and happily. Capacitors (as in spec sheet) just smooth this...
  8. O

    LM338/LM318 Not enough power. Vref drops!

    Hey. Thanks for your help. -------------------- Well, actually I don't have a heat sink since I'm using a protoboard and there's not enough room for it. But well... in fact, it doesn't get that hot because it's just draining 1.33 Amp @ 3V (remember the huge drop in Vout). ---------------------...
  9. O

    LM338/LM318 Not enough power. Vref drops!

    Hello. I need a regulator to deliver 5 Amp, at 7.5V to a servo motor I'm trying to drive. I use nearly the same simple schematic as in LM138/338 datasheet (page 5) in Application Hints. I'm using an 11.1V Li-Poly Battery. With no load, the regulator seems to work properly with 7.5 V at the...
See more
Top