A few mods/projects for my TaoTao Atm-50 A1 By glavey (Read 25,098 times)

[glavey]

Sept 4, 2014 17:42:49 GMT -6 jct842 said:

There are lots of posibilitys for the changes you state for the screen. Controls dirty, sockets bad or loose, resistors burnt, and just about any component inside can change with temp. Those scopes were not very stabil when they were new, just better than guessing, or nothing. Gently tapping side of tubes one at a time might reveal a noisy one, stay away from banging on the 1v2...its working.

When new you could actually measure ac voltages and one grade better scope could measure dc voltage.

I spell bad, my scope is a tektronix, it is newer than I imagined and heavier with around 50 tubes! Just looked and I found more out about it than I knew. www.barrytech.com/tektronix/vintage/tek533a.html

check the manual page it may have a link for your scope too.

I crapped my self when I saw all those tubes.

I'm very close to possibly buying this scope. It's quite old and only has 20MHz bandwidth, 10M samples/sec, 2k memory depth, but for what I will use it for (and for the hopefully cheap price) it will do just fine. One worrying thing is that I cannot for the life of me find a schematic for it. I can find the instruction manual and service/calibration manual, but no schematics.

Edit: Decided not to get it.

[jct842]

Best off to read up first, then look for one grade above tv servicing scopes like that b&k. A dual trace is worth its weight in gold compared to a single trace. skip the heathkit, sencor, paco, b&k, eico and any that the time base is calibrated in freq.khz,mhz.) The better ones the horizontal time base is in micro-sec. If I were to be in the market a triggered dc dual trace with at least 20-30mhz bandwith. The higher band width produces a more accurate wave form with sharp corners on a complex signal. I think first you need to have a need!

[cyborg]

You guys lost me at tubes,,, what in heavens name would you use one of those for?,,,

[Guitarman]

If you know how to use one, you should be able to scan a CDI and see if its waveform matches 'normal'. If it's off spec then it's bad.

[glavey]

Sept 4, 2014 21:46:22 GMT -6 cyborg said:

You guys lost me at tubes,,, what in heavens name would you use one of those for?,,,

Lets say you wanted to measure the voltage coming from the ignition trigger pickup, which is one of the things I will use it for during my tach project. You can't use a multimeter because the voltage spike is so short that it just won't register on the meter. An oscilloscope can measure things that happen in 1/10,000 of a second or shorter, something no multimeter can do.

Also aliens use them very frequently when they abduct you (oscilloscopes and aliens use probes to get their information).

Here are 2 more scopes I am looking at: Tektronics 2210 and Tektronics TDS 224. I'm a little concerned that the 2210 didn't have its digital function tested, that is what I am going to mainly use. The TDS 224 usually goes for more money than is in my budget for a scope, nevertheless, I could still get lucky.

[glavey]

I left my scope on for a couple hours showing the same waveform. Eventually the screen started to dim enough that not all of the waveform was being displayed; there were parts blanked out and the trace line became thicker and impossible to focus. Yes, I did turn the intensity all the way up, still blank spots.

Oh well; it is another (refurbishment) project for another day.

[jct842]

screens burn if left on a trace that long. If one needs a trace on to monitor some thing you turn brightness way down, maybe the newer scopes can handle it but the older ones couldn't. Better read more on them.

[glavey]

When the trace was left on for a couple hours, I turned the intensity all the way down. I only turned it back up when I checked on it. Also, it wasn't a static trace, it was scrolling across the screen so no one area of the screen was continuously left on.

I will read up on scopes for the next few days.

[glavey]

Here's another one I'm looking at getting if the price stays low.

Edit: Got it.

[Bashan]

You can measure trigger voltage with a meter. Are you referring to something different?

[glavey]

Possibly, I was and still am a bit scatter-brained.

[glavey]

Well, I've been running "hello world" programs (I guess they are called sketches when working with an arduino) with all of the electric parts I bought. So far, every piece has worked perfectly. I still have yet to test the motor driver with one of the stepper motors.

[glavey]

Sorry for the lack of updates, there was an unfortunate and tragic event in my family. I'm still going to continue with this project, although I probably won't update this thread as much as I did previously.

I've tested the 16x2 character display and it works great. The backlight is brighter than I thought it would be. The response time of the display is about what I thought it would be; 500ms and you can see the characters clearly, 400ms and it gets a bit worse, 300ms and you really struggle to see them when looking at them head-on, on the scooter where you just glance at the screen to see the speed would be impossible. I'll use this display for slowly updating or non-critical data such as oil temp, voltage, fuel level, etc.

The 8 digit 7-segment display gave me a few problems at first.

One being a lack of explanation of the library functions to control it, but I found a page that explained everything I needed to know.

Second, I was having some trouble with the display showing erroneous readings, lighting up segments and digits which I had not sent it code for, and going into shutdown mode when no such code was sent. Turns out I need to add some bypass caps to it, even though the display board itself has a bypass cap on it. I'll ask around on some electronics/arduino forums to see what exactly I need to do.

As for the motor driver and the stepper motors, I haven't tested them yet for a few reasons.

One being that I would need to solder on header pins to the driver board to test it, and I intend to, during the final assembly, use wire to connect all the different boards together and I don't want to unnecessarily heat up and potentially cause damage to the driver board if I don't have to.

Two, you tell the driver board how many steps to move the motor in a particular direction by pulsing a certain pin x-number of times. This could be difficult to do because I am going to be using the arduino's interrupt to count the revolutions of the engine and if an interrupt were to happen while the arduino was sending out those pulses, there would be a delay in the pulses and the motor driver might not move the correct number of steps. Again, I will ask around on other forums dedicated to electronics for some solutions.

The dc-to-dc buck converter works perfectly. In only it could handle reverse current/voltage, then I could use it as a charging regulator for my scoot.

The hall effect sensors work well, some of the silk screen on the boards is in (I think) chinese, but I figured out that one led is power and one is when the sensor goes high. The sensor triggers when I move a magnet about 3mm from it, but it only works with one pole of the magnet. Hopefully the magnet on the flywheel will have the correct pole pointing outward.

I'm still waiting for the scope to be shipped, so no news on that front.

I went for a ride today to help calm me from the stress of the family issue. During the course of that ride, I had an ambulance come toward me on the opposite side of an avenue. I only noticed it because all the cars near me started slowing down for seemingly no reason, and then when I saw the lights flashing I knew what was happening. Only when the ambulance was within a few hundred feet of me did I hear its sirens. I couldn't hear the sirens over my scoot's induction sound caused by the pod filter. That made me realize I really should look into a way to reduce the noise from that.

The only way I can think of to do that is to make some kind of an enclosure for it, or maybe to have a pipe of some length between the carb and the filter.

What is it about the stock airbox that makes it so quiet?

[jct842]

It looks as if you got a real good deal on the scope. It does't say there is a probe included but in a pinch you can make a useable one. With instructions you should be able to find on the net. I built one for my scope. A new correct one is tuneable and kind of expensive. Might find one on fleabay. Scope beats mine by 50 miles!

[jct842]

Stock air boxes have baffles. I ran the majesty with one of the filters off and wanted to see if idle speed changed much if I pushed the filter in place with my hand. The intake made much more noise than the muffler.