Asked by 946582f 9 years ago | last reply 9 years ago
I'm thinking of replacing some electrolytic caps with smaller ones to save space. Foresee any problems? I was thinking tantalum just because they looked like they might be smaller. This is for a AAA 1.2-1.5V circuit.
Posted by royalestel 11 years ago | last reply 11 years ago
Howdy all, Recently got back into basic electronics and have started building kits. Been building a kit that uses tantalum capacitors and it notes that polarity orientation is very important. The question I have is: is there some un-published indicator of how polarity is indicated on these tantalum caps? I've been over these things with a microscope, even bought new ones, but other than the values & manufacturer, I can find no obvious sign of polarity. Leads are the same length and not marked. What am I missing? Thanks in advance for any help. Dave
Posted by gutbucket 6 years ago | last reply 6 years ago
Hello .im making a TubeScreamer TS808 clone. In the original schematic they use 2 0.22uF Tantalum capacitors, but i don't have them, so i replace with 0.22uF Mylar capacitors.The result is when i turn the tone pot up, i get noise and loud hiss. Can i replace the 0.22uF Tantalum with 1uF Tantalum then change the value of some resistors to make the tone pot to work ?This is the original schematic and my modified version .I not tested it yet because i have to order parts to build it.Can you check it for me please! Im beginner and i dont know what part i have to replace if i replace 0.22uF capacitors with 1uF capacitors. Thanks! and sorry for my bad English! http://i247.photobucket.com/albums/gg132/chipmapple/tonechange.png
Asked by login721 6 years ago
See the schematic and these are the parts and please make a breadboard version IC1: LM555 Timer IC Q1: 2N3906 PNP transistor R1: 100K potentiometer R2: 3.9 Kohm resistor R3: 10 Kohm resistor R4: 47 Kohm resistor C1, C3: 0.01-µF disc (non-polarized) capacitor C2: 1.0-µF electrolytic or tantalum (polarized) capacitor Speaker: 8-ohm, 0.5-watt speaker(i also tried a buzzer) Photoresistor: I used a LDR aren't they the same? The buzzer goes off(not off. it's like explosions"The bomb went off") when light hits the photoresistor.
Asked by Hafiz Mohammad Shayan Tariq 6 years ago | last reply 6 years ago
I am amazed at all the great responses I got with my last question, thank you all! :D Though now I have a few more: 7) Should I try to learn how to work with complex impedance (capacitors, resistors, and inductors in all sorts of weird configurations) Also, can I treat reactance in general as a resistance when looking at capacitors in series or parallel with resistive loads and stuff? For example, can I simply add up Xc, Xi, and R for a total impedance? Or do I have to worry about phase shifts and stuff? 8) Is it OK to say that "Q" or charge is a more theoretical physics concept and is not too important with practical electronics? (C, V, and I being more of the focus and "ignoring" Q is OK?) 9) I have added a few of the "slides" and sneak-peaks to my upcoming video. If anything is wrong don't hesitate to nitpick and point it out! 10) capacitor fall under 2 major categories, polarized and nonpolarized. 10a) [under the 'polarized' branch] Electrolytic and tantalum capacitors are used for bulk filtering, but are evil and do not tolerate overloads particularly well. Especially tantalums. They tend to be available in huge capacitances, but can be "leaky" and have high ESR and series inductance. 10b) [under nonpolarized branch] Ceramic capacitors are the most common type of capacitors, and come in a few types. Generally used for local decoupling. They are pretty robust and tolerate overloads. Film capacitors find more use in high voltage applications, have lower leakage, better high frequency performance, and certain types have self-healing properties allowing them to tolerate overloads and surges the best. Mica capacitors are generally the most stable, with the lowest leakages, so they find uses for more critical analog applications.
Asked by -max- 2 years ago | last reply 2 years ago
Guess what I acquired :) It sings and vacuums and is a robot :P Roomba! It's a first gen (I think), but it was cheaper than a new battery - and it came with a new (in box) battery :PThe problem came when I went to charge it. At first I thought it was fully charged - and the battery acted like it was (1 hour+ of runtime on carpet). But now, it won't charge.Skip ahead some time.I've narrowed it down to this component (see image). When I spray it with canned air liquid - the charger comes back to life. Not to mention, it looks scorched.I'm fairly certain it's a tantalum capacitor. Except, the PCB marks it as "F1" while other tantcaps are "C#" designated. Can anyone confirm/identify?Oh -- it's currently charging with the charge cct in the refrigerator. I'm using a Kill-o-watt to see if it overheats (current drops off) :P I'll be modifying the case with a cooling fan once I've replaced the component :)I've got to say though -- it's really fun to watch is honestly pretty effective and getting stuff out of our "clean" floor :P
Posted by trebuchet03 11 years ago | last reply 11 years ago
I have been wanting to build a good amp for a while now and i just got a LM1875T. so i put together this circuit diagram: http://imgur.com/ov3Ikd6 also i am running the audio signal thru an LM386 as a pre-amp/buffer before it hits this. i am using a speaker rated at "4ohm 80W" and i am using a 30V 2A power supply. my questions: #1 the circuit does not run at all if R2 (22k between pin 1 and ground) is there so i removed it for testing. why is it there if it keeps circuit from working? #2 C8 (100uf capacitor between pin 3 and ground) is reversed? i thought it might have been a typo on the Texas instruments site so i put it normally. nothing happened. so i put it the way they showed it and it worked! but my cap blew 5 min later... (i used a 50v 100uf) so i replaced it with a 200V 147uf capacitor. it started heating up after 1 minute so i disconnected it to come ask. should i use a tantalum 50V capacitor?
Asked by TK175672 4 years ago | last reply 4 years ago
Hi, i have a 1963 VW bug that is very stock, but the 6v lights just dont work very well (dim at idle, then not too bright at speed) it is very simple to use a later 12v generator and then swap out all the lights, battery, coil and relays and it works great. BUT i have a 6v wiper motor and also a 6v gasoline heater that i will need to keep at 6v (the 12v parts are just not available or too expensive) I have found an article that recommends building a cheap voltage regulator using a 7806, ( 6 volt, 1 amp regulator) and 2 1uF 35v tantalum capacitors, then a NPN transistor which the original poster says is a 2N5881 npn transistor. here is the scematic. the pdf article is attached and the link to the original article is here http://www.studebaker-info.org/tech/6-12V/6-12-6.html The questions i have 1. what is a 2n5881 been replaced as? i cannot find it at jameco and the original posted doesn't give any specs for it. 2. how would i "pump up" the amps available from 10 to anything else (looking for about 15 amps) thinking that the npn transistor is the key but i am new to this and wouldn't even begin to know where to look. 3. what happens if any item fails? can i put some sort of safety into this so it quits rather than passing any addition voltage through additional info the heater runs at about 85 watts so 85 watts / 6volts = 14.616 amps the wipers run at much less than that so building 2 of this would work great. Any ideas? Thanks in advance for any insight to this
Posted by starvin 6 years ago | last reply 6 years ago