Author Topic: 5v regulator umiinit (Read 946 times)

chicobulilit · « **on:** February 07, 2011, 08:08:41 PM »

i have 5v regulator that supplies 3 7segdsply(from e-gizmo) and a 555 timer.....

my question is bakit umiinit ung regulator ko as in exage na xa.... pag direct ung connection papunta dun sa 3 7segdsplay.. meaning walang resistor in between.... kasi kung gagamitan ko naman ng resistor more or less nasa 200ohms 0.25watts ang hina ng intensity ng mga 7 segment display ko.... parang wierd kasi ... ngaun ko lang naencounter....

Philippine Electronics Forum · « **on:** February 07, 2011, 08:08:41 PM »

Macgyver · « **Reply #1 on:** February 07, 2011, 08:22:08 PM »

depende sa input voltage ng regulator mo. Kung 7v input meaning 2volts * current used by your circuit ang kailangan idissipate as heat.

kung 12v input mo, meaning mga 7v * current ng load ang icoconvert to heat. So talagang iinit sya.

Then kailangan mo talaga ng current limiting resistor for each segment.

Philippine Electronics Forum · « **Reply #1 on:** February 07, 2011, 08:22:08 PM »

chicobulilit · « **Reply #2 on:** February 07, 2011, 08:36:14 PM »

input ko po is step down transformer outlet ung pri tapos 15V secondary...... tska may bridge rectifier na 1A...... pwede kaya kung magseries ako ng load before the regulator..... ? like limiting resistor para di na ako magreresistor sa segments para mataas ung intensity ng mga ilaw ko or gamit na lang ako ng mas mababang value ng limiting resistor para sa mga segments ko?

Philippine Electronics Forum · « **Reply #2 on:** February 07, 2011, 08:36:14 PM »

marcelino · « **Reply #3 on:** February 07, 2011, 08:41:05 PM »

tama si macgyver... perhaps yung lower voltage secondary nalang ang gamitin mo.

may kakilala nga ako, ang ginawa, from like 15-18V------ 7812-------------7808-------7805. wala ngang init, pero magastos.

yung voltge divider may work, but carefully calculate the power dissipation by the resistors.

Philippine Electronics Forum · « **Reply #3 on:** February 07, 2011, 08:41:05 PM »

pEN DoTA · « **Reply #4 on:** February 07, 2011, 08:46:46 PM »

Quote from: marcelino on February 07, 2011, 08:41:05 PM

tama si macgyver... perhaps yung lower voltage secondary nalang ang gamitin mo.

may kakilala nga ako, ang ginawa, from like 15-18V------ 7812-------------7808-------7805. wala ngang init, pero magastos.

yung voltge divider may work, but carefully calculate the power dissipation by the resistors.

magastos nga. daming components.

Philippine Electronics Forum · « **Reply #4 on:** February 07, 2011, 08:46:46 PM »

chicobulilit · « **Reply #5 on:** February 07, 2011, 08:49:42 PM »

Quote from: marcelino on February 07, 2011, 08:41:05 PM

tama si macgyver... perhaps yung lower voltage secondary nalang ang gamitin mo.

may kakilala nga ako, ang ginawa, from like 15-18V------ 7812-------------7808-------7805. wala ngang init, pero magastos.

yung voltge divider may work, but carefully calculate the power dissipation by the resistors.

oo nga.... wenks..... nakalimutan ko un......buti na lang meron pa akong spare na may 2 outputs.... salamat sis!

rdpzycho · « **Reply #6 on:** February 07, 2011, 08:51:37 PM »

Quote from: marcelino on February 07, 2011, 08:41:05 PM

tama si macgyver... perhaps yung lower voltage secondary nalang ang gamitin mo.

may kakilala nga ako, ang ginawa, from like 15-18V------ 7812-------------7808-------7805. wala ngang init, pero magastos.

yung voltge divider may work, but carefully calculate the power dissipation by the resistors.

pwede namang multiple resistor na 5W din sis. ganun ginagawa ko dati.

@TS: calculate or measure niyo 'yung current na kinukuha ng load. tapos compute niyo 'yung power dissipation nung 7805. 2W lang ang kaya ng TO-220 package, above that dapat meron ng heatsink.

taqui · « **Reply #7 on:** February 07, 2011, 08:53:46 PM »

TS kulang sa current, anung gamit mong regulator na 5v? palakasin mo current,dagdag lang ng isang transistor.,ok na yan

chicobulilit · « **Reply #8 on:** February 07, 2011, 09:29:33 PM »

solves na po... just used another transformer... ung may 2 outputs... so 6V na lang input nung sa regulator.... and it even makes my circuit less components....salamat sa lahat ng nagcomment.... noted po lahatQ!

BANNEDMemberAccount · « **Reply #9 on:** June 21, 2011, 05:31:09 PM »

Quote from: marcelino on February 07, 2011, 08:41:05 PM

tama si macgyver... perhaps yung lower voltage secondary nalang ang gamitin mo.

may kakilala nga ako, ang ginawa, from like 15-18V------ 7812-------------7808-------7805. wala ngang init, pero magastos.

yung voltge divider may work, but carefully calculate the power dissipation by the resistors.

tama nasa isip ko

http://www.electronicslab.ph/forum/index.php?topic=26958.20

problema korin ito sa 7 segment, ito rin ang nasa icp ko kanina gawin kasi umiinit, confirm na

??? · « **Reply #10 on:** June 21, 2011, 09:34:36 PM »

Taas rin kasi input voltage mo ate red eh.

Philippine Electronics Forum · « **Reply #10 on:** June 21, 2011, 09:34:36 PM »

Philippine Electronics Forum