200 Example Transistor Circuits

slimplynth

Senior Member
Itching to ask a question about the blimp but which question? And when should it be asked? Further reading isn't helping.

I want to change battery, too many changes too many options and too many other problems. Which seems at this... ahhhh dag nam it... I won't ask :D

Yes I will :)

I want a Lithium based battery and charger, do any forum members who have been using these for a while (please state) know of any make/model (ideally charger too) suitable for powering:

One 08M
Two 20X2's
Three Pager - RPM2 motors (I hope they'll be enough)...

Argh this is frustrating, My bot is nothing like the blimp... hold my hand up, should have tried harder to make the bot more similar to blimp.

The bot uses 3V geared motors, the H-Bridge controller comprises DPDT relays... too heavy to fly.. a 3V H-Bridge is probably doable (with more searching - possibly a L298) though I can't help but think I should swap battery now to avoid reworking later on - always wanted a wireless cam, got the micro-cam (works at 6V), need a wireless AV sender-light-as-possible-transmiter.)

Swapped motors saving 20g (ish)... done away with a 9g servo for control but want to keep it for a ballast control mechanism.

Feels like i'm about to ask, "How can I use a picaxe to steer my car" but...

Thinking Lithium and thinking awwww I didn't want to... 7.2v and light weight sounds too appealing to ignore (Don't think Hindenburg whatever you do)... if anyone wants to volunteer a tried and tested battery + charger... thanks in advance.
 
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BeanieBots

Moderator
We can do the battery and weight stuff later.
First, get a working bot so that you know you can control it in a manner safe (for the blimp as well as you) enough to avoid tears.

LiPo technology warrants a thread of it's own but there are plenty of ready-made packs & chargers available so don't fret over that issue. Let's see a controlled bot first. (one step at time;))
 

MFB

Senior Member
Although there is a place for this type of ‘cook book’ collection of circuitry, more background knowledge is required to debug and customize these designs than would be the case when experimenting with software. Unless you have access to a pretty good circuit simulator it is all to easy to damage electronic components or, in the case of battery chargers, yourself.
 

Dippy

Moderator
Well, of course it's not perfect for everyone (what is?) , but surely anyone learning electronics should also be collecting information (examples) as well as learning the basics?

And many people here are well past Newbieness. Older hacks often just need a reminder of an application to bring it all flooding back and don't need a page of text description.

Once the basics have been absorbed by the punter , then these types of webpages can be part of your Grimoire (Book of Spells).
Once you have a Grimoire and made some notes then you don't have to go to Forums and ask about LEDs and resistors.

Why a simulator? What's wrong with half a brain and some learning? :)
 

Goeytex

Senior Member
Why a simulator? What's wrong with half a brain and some learning? :)
Hopefully you don't suffer from the delusion or errant assumption that those who use simulators have less than half a brain. A good SPICE program can be a very useful tool even for those who fancy themselves above using a simulator.

For one, plugging circuit found on the internet can sometimes show if that circuit will actually work. I have found quite a few that are pure junk.

Using the transient analysis feature can show voltage and current at any point in the circuit allowing the designer to make needed corrections that can
optimize circuit performance & efficiency.

Simulations make "what if" changes fast and simple, eliminating the need to physically change an/or purchase components that may not be needed in the final design.

I can think of lots more.

Many die hard anti-SPICE folks errantly and ignorantly assume that those that use Spice are lazy and stupid and that these lazy, stupid, SPICE people think that Spice is the Alpha and Omega of circuit design,.... when the truth is that any good designer or student simply uses SPICE as a starting point and as one tool of many, and understands that SPICE is no substitute for actually bread-boarding and testing a design with real components in real world conditions. :)

Goeytex
 

Dippy

Moderator
Of COURSE I realise that simulators can be handy.
Of course I realise their tremendous benefits in experienced hands.
Of course I'm not suggesting that Sim-users don't have half a brain or are lazy.
Of course I'm not Anti-Spice , I use it too sometimes for ballpark before breadboard and proper testing.
Of course I realise the benefits of using a simulator to demonstrate.
Of course you have to have half a brain (at least) to operate a simulator - after all, 'rubbish in = rubbish out' eh?
(That was a joke by the way....)
And, of course, if I was paranoid I'd think you were having a pop.;)

I think you have over-read my comment.
It was intended to be light-hearted, not some deep and accusatory statement of fact.
But I still maintain a newbie should have basic knowledge before being thrown at a simulator.

I really don't want to initiate a deep and meaningful discussion on My Favorite Simulator so I'll leave it at that.
If the link helps - store it. If it doesn't then don't. Simple. Job done.:rolleyes:
 

Goeytex

Senior Member
Dippy,

Your comment on simulators seemed to be a reply/rebuttal to what the
previous poster said. That's how I read it in the context and flow of the dialog.

But I still maintain a newbie should have basic knowledge before being
thrown at a simulator.
If you had actually stated that previously in the thread, I may not have
bothered with a reply at all.


Glad we got it cleared up.
 

slimplynth

Senior Member
Only meant to be reading blimp related this week but couldn't resist...

Not used any simulators to date (perhaps I should have:confused:)

It (the site linked) maybe cookbook in nature but then I think that everything I've had to learn (technically) since leaving uni has tended to be this way of thinking... HTML, Javascripts, AHK, SQL, XML... take an example from the web and try to change it to fit your own needs.

Just thought the images might assist someone, the presentation was the thing that appealed to me, short and snappy.
 

manuka

Senior Member
That "200 Circuits" mention links to "Talking Electronics" guru Colin Mitchell,who is apparently close to e-retirement in favour of things e-political. Colin has long been a nifty circuitry legend down under -his booklets & colourful schematics are very engaging (sample below)!

Many of his classic circuits now suit PICAXE enhancement,so I contacted him about this some years back. However he seems to have settled on raw PICs... Stan.
 

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moxhamj

New Member
That link is gold, thanks slimplynth. Some very interesting radio Rx and Tx circuits.

Are you building a blimp? Looking for motor, prop, lithium battery, charger, ultra light construction etc?

This is thinking laterally, but I wonder if you could get all those bits out of a RC helicopter? I've bought quite a few off a four letter website starting with e, and they are only $20 or so each. I've crashed many. I've also got really good at pulling to bits the crashed ones and recycling all the components into new working ones. So I can say that they are pretty easy to pull to bits and rebuild.

The tail prop could be perfect for a blimp and would have a very long running time.

I wonder about this for a crazy suggestion; - buy a couple of these helicopters. (search for helicopter gyro). Fly them and have some fun. Eventually you will crash them. But this is a good thing! Now you can justify pulling them to bits for the parts.
 

slimplynth

Senior Member
Cheers Doc, Yeah I dismantled a cheapo RC plane the other night.. the battery is a 3.7V Li-po (or Ion i think).. was always against this because of my inexperience with them.. though I can't be ignorant forever.

Had considered using the remote from the dismantled toy, I'd still be short of controls for the "vectored thrusters" (VT) - not trying to sound smart there.. just a term that was used on Blimp***** site and makes understanding easier. Decided I dont particularly want forward/reverse control on the VT's because of the extra complication and weight but can be added if needed later.

The 3V is really a strangle on further work... the voltage drop across an H-Bridge at this voltage makes the setup useless. 3V will remove the option of IR coms with a TSOP18 or a 433 rx... I think I may have to concede and use an additional CR123 (@20g)... which I suppose is ok, I've shaved that off by using alternative motors. The weight save was for a cam but thinking now... that can wait til I have something airbourne... someone on here no names mentioned (BB :)) has mentioned in a few posts about taking one step (prob) at a time.

Yeah.. I've decided.. extra CR123 it is. 6V will just make life easier in the short term and give me greater fuel reserves to go at during testing (waiting for a digital compass to arrive - Cpt. Slim at your service :)). Will look at moving to more dastardly Lithiums when the circuits are tried an tested. I say circuit but the plan is to use Kynar to save on weight so imagine the dangers of a mis-placed connection having terrible consequences with a Li-po being to great to accept.

Next problem:- a light weight (reliable) battery holder for 2xCR123's in series - Shrink Wrap maybe, idea of holding a lighter over a battery (twice) seems a concern though.

edit: Looked at DC boosters too but was unsure if I'd be just spending more money with no gain.
 

Dippy

Moderator
I haven't been following this Slimmy so I don't know what your electronics design looks like, but have you thought about MOSFET design for H-bridge. This would (with care) minimise any drops. I'd avoid bjt type stuff in any event where possible.

Heatshrink sounds bodgey (sorry mate) and I bet it would be unreliable.
Some people will fidget at the mention of liths in series... (enter Googlers).
Maybe a couple of 2/3A battery holders, or a DIY jobbie using those cheap battery springs that Farnell and others sell?

"Looked at DC boosters too but was unsure if I'd be just spending more money with no gain."
- is that a fishing-for-a-long-debate question?
With revised design do you need a boost?
If so, have a think. Look at the specs of whatever device you need. Look at the downsides (you been on this Forum long enough to know those by now :) ).
 

slimplynth

Senior Member
True true, will scratch my chin on the drive home and give it all some thought. Weight limit is a killer though 125g max.
 

slimplynth

Senior Member
calculator!! you must be joking :D I've not read a single datasheet or anything, was hoping you'd all do that for me :p (I jest of course) What i really wanted was suggestions of tried and tested Li-po battery packs with chargers for sale in the UK..
 

Dippy

Moderator
"What i really wanted was suggestions of tried and tested Li-po battery packs with chargers for sale in the UK.."

- blimey, I couldn't get that from the previous posts ....:confused:

The best way to find that out is to start a thread asking "Can someone give suggestions of tried and tested Li-po battery packs with chargers for sale in the UK"
- no clairvoyance required (that is a JOKE by the way, a joke, haha.. etc.)
 

InvaderZim

Senior Member
I've seen batteries spot welded for consumer electronics (a shaver); likely the heat doesn't really penetrate the battery case during a brief weld. I soldered one once, and attempted to make it a quick touch of high heat; don't know how that affected the life of the battery, but nothing blew up in my face. Take safety precautions just in case. I'd try the shrink wrap on a lark, it's easy and there's very little consequence if it doesn't work.
 

Dippy

Moderator
Spot welding is done all the time without reported detriment.
Millions of coin cells and other cells with tags and tabs etc.
And axial wired batteries too.
I guess it depends who is doing the welding or soldering...;)

When you say "shrink-wrap" are you on about heatshrink tube or tape?
Yeah, go for it, why not. I'd be surpirsed if the batts maintain contact without some help.
 

BeanieBots

Moderator
Weight limit is a killer though 125g max.
That's not a limit. You could lift half a dozen complete model helicopters and a video camera:eek:

As suggested by Doc, maybe get yourself the guts from some old helis.

As for soldering to batteries, a few cautions.
It CAN be done but make sure you use a powerful iron (100W+) to avoid needing long term heat. If soldering to an AA or similar type battery, be very careful not solder over (and hence seal) the gas vent which is often the middle of the +Ve terminal.
Some batteries are stainless steel, these need acid core solder which is nasty stuff and I'd suggest avoiding if at all possible. (use an old iron).
 

slimplynth

Senior Member
That's not a limit. You could lift half a dozen complete model helicopters and a video camera
Its ok, I've rigged up some invisible thread... the video will clearly show it aloft... it's all smoke and mirrors.

In all seriousness though, it's daunting how quickly all the little things start to add up. I also want a decent share for ballast release.
 

BeanieBots

Moderator
Just teasing;)
However, as far as model aviation goes, that really is quite a lot.
Good to see you are thinking of ballast. Even the aluminium coated materials can let helium pass through at an alarming rate:(

I still think you should be doing a lot more "ground" work (pun intended) so that the ONLY issues you need to worry about once taking to the skys are ones of lift/weight & airodynamics rather than, "how do I steer", "how do I drive this motor" or "how do I measure distance" etc, etc.
 
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