In just bought a dso. No real reason for spending the money other than I always wanted one. I'm telling myself it's an investment since my daughter has been accepted for all 4 of her engineering u'grad programmes next year.
My budget doesn't run to buying a full featured function generator to enable elaborate 'scope practice so I'm looking at alternatives and would appreciate your thoughts.
It seems analog chips like the ICL8038 and its derivatives have fallen by the wayside, although my local supplier seems to have stock. Expensive for what they are, imo, but simple enough to rig for simple use.
Good old 555 gives a square wave and I've seen simple external circuitry that can eg make that into a sine wave.
Probably the easiest is to dead-bug a 555 like this and add the 2x caps and 1x resistor needed to get an ac sine wave.
Thoughts?
(Bear in mind, I have no need for a generator other than to feed stuff into my 'scope: so the actual characteristics of the wave are not important. Being able to change those would be good though.)
Yep it has normal USB on front for a flash drive, and a USB-B on the back to hook it to PC. Came with CD of EasyScope so it's mimiced on the PC screen. In fact can drive the scope from the PC, it has a graphical layout that looks like the hardware and mouse-click the buttons. Or can capture a bitmap of the scope on the PC screen, see attached example.
The scope also supports PictBridge for direct printing but my home printer doesn't have that facility.
LarryD:
Try the XR2206 for your Function generator.
Just waiting to hear if my local guy has stock....
What's the minimum external circuitry it needs for very basic functionality? Do you have a link?- the ones I'm finding are complex, for a good range of functions.
As mentioned you can use an Arduino also.
Has the power to be programmable (use direct port manipulation).
For example produce 100 - 10uS pulses out every 10 seconds.
Maybe put a Pro Mini in a small box with FTDI out to the case for programming.
Also have a few outputs on a DB-09 female connector. 1HZ, 10Hz, 100Hz etc.
Add some PWM for servos.
Maybe a pot to vary the frequency.
LEDs, Bubble-Luscious ten minute air supply, wheels Sorry caught in the moment.
Yep and indeed I have been: proving the RC theory for a variety of R's and C's with blink. Blink's delay = 5T and discharges when full, delay > 5T and it stays full a while longer, make delay too short, and it gets snipped and triangle-like. Learning a lot about the 'scope, and re-hashing stuff I probably covered in u/grad physics 40y ago.
I'm actually thinking to get a decent analog "lab book" somewhere- Google is my friend- and bone up on all that stuff.
Here's an interesting snippet I picked up on good ol' YouTube: 63% of 8 is 5 (among friends anyway). So if you scale your RC output voltage to be 8 blocks high on the screen, T is where the trace crosses the 5th horizontal. That's a cool tip....
BTW, in a world of badge-engineering, the Rigol scope here and here is esentially the same. Minor differences in controls but the menus look identical afaics.
Vaclav:
Does't your scope have a "calibrate" feature? My analog Tek 464 does.
Usually 1kHz / 1mw square wave source to calibrate probes.
Indeed it does; but as a newb 'scope user, I want something to provide me with a variety of signals so I can play.
As an aside, on using the equipment to calibrate itself, how does one know the test signal is correct 8). (Like the wheel tapper who condemned a whole train but then found his hammer was cracked....)
I had trouble getting the 8038 to wotk, perhaps a breadboard capacitance issue, so I changed tack.
Prompted by this EEVBlog, I decided to see if I could unravel the IR codes from my Philips remote. I already knew from using it with a TSOP and IRremote library it uses RC5 prootocol, so I looked that up here.
First I used a plain old photodiode to throw the raw input from the remote into the scope and check it against the top part of the pic in that link. Then I used a TSOP (much tidier output) to verify a number of button pushes against the expected codes from the tables in that link.
Learned a lot about using the scope.
I'll do it all again and capture screenshots from the scope and post them here one day soon, as well as schematics of the connections. That might help someone, so watch this space.
Sorry caught in the moment.