Search found 235 matches

by Dimbulb
Sun Sep 02, 2007 10:45 pm
Forum: General Discussion
Topic: fax to email
Replies: 6
Views: 2862

by Dimbulb
Fri Jul 13, 2007 9:13 pm
Forum: General Discussion
Topic: Over 100 percent energy machine?
Replies: 59
Views: 9539

by Dimbulb
Sun Jul 01, 2007 9:06 am
Forum: General Discussion
Topic: 6 Radios to One Speaker?
Replies: 70
Views: 12658

Years ago I had a bunch of radios and scanners connected to a diode mixer that was fed into an to a amplifier. several channels were too loud so I tried to attenuate them. The speaker cabinet for voice had a midtone 8 inch speaker that sounded much better than the audio from the radios. The antenna ...
by Dimbulb
Tue Jun 26, 2007 11:18 am
Forum: General Discussion
Topic: Will cars ever run on pressurized air?
Replies: 61
Views: 15339

I would like to read The stories written bya reputable third party.

I would like to see a contest between electric hybrid and rotary air hybrid.

while it is possible I am not sure of the merits yet
by Dimbulb
Wed Jun 20, 2007 9:17 pm
Forum: General Discussion
Topic: Prius VS Hummer
Replies: 11
Views: 2733

For 2007 the gas engine is 76 HP plus the two electric motors 28 HP equals 106 HP. my own testing showed this: 45 mpg hywy 53 city The savings are relative to what you drove before. The sticker price of 22,950 / zero package. The average driver in the bay area drives more than years before. let's sa...
by Dimbulb
Fri Jun 15, 2007 8:05 am
Forum: General Discussion
Topic: How do I Fine tune a 78L05 ?
Replies: 50
Views: 11593

The regulator is working ! After a night's sleep I re- read the last post. I removed the 10k resistor from the cathode of the LM431 and soldered it to the emitter the results are no drift 5.028 V I am very pleased with this circuit. The quiesent current of 4.85 mA I have mounted new parts on a pcb, ...
by Dimbulb
Fri Jun 15, 2007 7:28 am
Forum: General Discussion
Topic: How do I Fine tune a 78L05 ?
Replies: 50
Views: 11593

thankyou I downloaded the manuals. the application: the application 100mA 5.000 V from a 9 volt battery, it is a supply for hobbiest that need a little more precision. some future improvements include a pre-regulator. Also getting a little more life from a 9 Volt battery. since most regulators take ...
by Dimbulb
Thu Jun 14, 2007 11:02 pm
Forum: General Discussion
Topic: How do I Fine tune a 78L05 ?
Replies: 50
Views: 11593

base to ground is 3.071 V ground to emitter is 2.510 V I think I need to re wire the transistor one moment please Chris: yes I begin: http://ffden-2.phys.uaf.edu/212_fall2003.web.dir/Dane_Lenaker/solid.shtm my final attempt tonight after rewire was the same. one final trial was adding 5k impedance r...
by Dimbulb
Thu Jun 14, 2007 10:49 pm
Forum: General Discussion
Topic: How do I Fine tune a 78L05 ?
Replies: 50
Views: 11593

I am getting 5.604
measuring voltage across the collector base
the voltage slowly drops as the battery drops.

a preregulator should improve this.

thankyou
by Dimbulb
Thu Jun 14, 2007 10:11 pm
Forum: General Discussion
Topic: How do I Fine tune a 78L05 ?
Replies: 50
Views: 11593

Please help me to understand the following: "These effects can be avoided by moving the top of the feedback voltage divider to the emitter of the transistor (the new output terminal)." I have two 10 K resistors the output at the cathode of the LM431 introducing the new transistor we connect the base...
by Dimbulb
Thu Jun 14, 2007 7:14 pm
Forum: General Discussion
Topic: How do I Fine tune a 78L05 ?
Replies: 50
Views: 11593

I am not a scientist or electronic engineer as a hobby and my goals are for improvement of this hobby for other hobbiest like myself. The focus is how to progress into completion of this voltage regulator. The LM7805 was unable to adjust upward. It is still a good regulator. The LM431 adjusts nicely...
by Dimbulb
Thu Jun 14, 2007 6:22 pm
Forum: General Discussion
Topic: How do I Fine tune a 78L05 ?
Replies: 50
Views: 11593

now that we're moving on from checking the meter. I am now using the LM431 with much success. National Semi's Data sheet example on adjustment using a voltage divider works nicely. What I would like to accomplish is to use the LM431 reference and follow it with something to source more current. on a...
by Dimbulb
Wed Jun 13, 2007 10:01 am
Forum: General Discussion
Topic: How do I Fine tune a 78L05 ?
Replies: 50
Views: 11593

I agree the capacitors are necessary as the circuit grows and the battery gets low. I was thinking that a tantalum on the output for quiet. This because I of reading some audiophile designers. on a separate post I would like to measure the noise but this needs to be a whole new post agree. now regar...
by Dimbulb
Tue Jun 12, 2007 8:46 pm
Forum: General Discussion
Topic: How do I Fine tune a 78L05 ?
Replies: 50
Views: 11593

yes again, I repeat that I can see 5 places I am now using an LM431 R1 and R2 .1% 10 K ohms I am now getting stable 5.029V at 4.85 mA I think 1% R will work I need to modify the divider. using a small 200 ohm 10 turn trimmer between resistors. 1% resistors will work thankyou for your encouragement t...
by Dimbulb
Mon Jun 11, 2007 10:20 pm
Forum: General Discussion
Topic: How do I Fine tune a 78L05 ?
Replies: 50
Views: 11593

experimenting as suggested. The 78L05 can be tweaked down nicely but I need to raise the voltage. I introduced the LM2931 LDO as a canidate however tweaking this output of 5.4V had the effect of raising the voltage. Thankyou all for opinions, the thermal issues will indeed limit module to about 18mA...