About Capacitors ... Part 7 Blocking and admitting signals.

Capacitors, when used in conjunction with inductors, can be used to separate different signals that travel down a common wire. In this video I show you how a capacitor blocks DC while admitting an audio signal. As with a lot of things in life the facts are not always straight forwardly obtained, we're told that a capacitor blocks DC, and that's true but it come with some additional conditions that confuse the issue.
I know I have a longwinded way of delivery but stick with it and you might just find it interesting.
Notes
I used 4.7uf capacitors as that's what I had to hand at the time.
At 1 kHz the impedance of each capacitor is 33.8ohms
At 3 kHz its 11.28 ohms and at 10 kHz the impedance is down to 3.38ohms
Thanks for watching Kind Regards ... Andy
11/11/11 I've just realised that I've drawn the chokes with a dotted line this would be correct for ferrite cores but the chokes in the video have iron cores, sorry.

[@monarchham]

You are so right, Andy! I am forever going back and reviewing first principles. I am amazed at how I learn something new every time. Your demonstration of putting multiple signals on a single conductor is one of those things I had forgotten. Thanks!! Winnebago was the name of the Indian tribe who lived here and was displaced by white settlers. Several wars were fought of this area and one of the famous warrior chiefs was Chief Blackhawk. Keep up the good work,Andy!! 73 Herb/WR9H

[@monarchham]

Thanks for the teachings, Andy! I am working my way through your stuff and find it all very well done! What was drilled into me by a radio instructor was this: capacitors oppose any voltage changes while inductors oppose current changes. You did a great job of explaining how capacitor selection determines which frequency of voltage we are choosing to allow or block....very cool... 73 Herb/WR9H

[@shiftgood1]

This is fantastic for my work with human robots. I needed this badly for a great deal of momentary switches. Of course, I must speak in addition to the slow car movement, part time for appreciation, publish on and off media, The Box Teleport club, Future Consciousness "sin" detection unit,a greeting for the Paradigm Shift for 13 to 27 years. Again, Mr. Andy Davies, thank you from the heart.

[@AllAmericanFiveRadio]

Neat demo Andy. Using two wire for more than one purpose, or more than one signal on a wire, like in radio is a very important concept to understand. Very nice explanation with a great practical demonstration. Regards Rick

[@miguelmouta]

Calm speech nevertheless deep teaching. Very efficient didactics. Thank You master, and best whishes from São Paulo.

[@AndyDaviesByTheSea]

Hi there, I’m glad that you found it helpful. Very often the more you learn about a subject the more you realise how little you knew to begin with. This little demonstration is only scratching the surface but hopefully it’s in a practical way which I hope is clear. I’m sure you could make a life study of capacitors and their applications as as I’ve said, the more you learn about them you’ll realise there are many levels of understanding. Kind regards ... Andy

[@AndyDaviesByTheSea]

@MrVinamp Yep, that’s right, the same thing also applies to the crossover unit in a speaker cabinet where you two or three speakers. A network of capacitors and inductors ensure that the low frequency bass notes go to the ‘woofer’ that can handle current and the high frequencies go to the ‘tweeter’ that can respond to rapid movement. Sometimes I think our ears work the same as if someone’s talking about us across a crowded room somehow we filter it out hi hi. Kind Regars ... Andy

[@cdray1968]

Thanks Andy. Good video! David

[@AndyDaviesByTheSea]

@migette1 Yes, I heard the news today, 31st Jan 2012, some bright spark has just realised that it would be good for the country if we had a few more Engineers in the UK. Man tell us something we don’t know. I’ve just reading Alan Sugar’s latest book and I can’t help thinking I agree with a lot of his thoughts on the subject. All the best ... Andy.

[@AndyDaviesByTheSea]

Thank you Kind Regards ... Andy

[@louparsons]

Andy, I've been stewing about 'capacitors don't pass DC' for some time, only once or twice (and in both cases on YT) have I seen something like the demo you just did, which seems to make the entire capacitor/DC/signal thing make sense. I don't understand why we're not taught about that 'instant' of charging. Thanks

[@AndyDaviesByTheSea]

@12ax7mod Thank you Jim, without feedback I never know if I’m doing the right thing or not. I know I can’t please all people all the time but I’d like to say thanks to everyone that has been so generous with their comments about my videos. Have you had a look at my ‘About Radio’ videos? 73’s ... Andy

[@AndyDaviesByTheSea]

@monarchham I guess they taught right Herb. I never know how much detail to go into in these videos. It seems that they have some appeal to folk that are just beginning to learn and it also appears that some of the ‘old hands’ like to look in and make sure I’m not saying anything too dumb. None of us are too old to learn something. I never knew that ‘Winnebago’ was a US county until I looked you up on QRZ. I always thought it was only the name of the best mobile homes. Kind Regards, Andy

[@AndyDaviesByTheSea]

@migette1 Hi Peter, you run the risk of upsetting a lot of guys and gals out there asking who remembers valves hi hi. But I’m sure you know that, there are probably some who would say that if valves had been invented after transistors it would have been a step forward. Sometime I must put a video on KZbin showing the 60KW water cooled industrial triodes I used to use, now that's a valve! Kind Regards ... Andy

[@MrVinamp]

Just like the intercom that works through the mains

[@dersg1freak]

wohoo i get to keeo my money! :D