Junebug help??

[3v0]

...how to make it come on at 25mph. thinking a hall effect switch or ?? on a wheel or ??
I was thinking a hall effect or IR/detector w/ fan in a tube.
just more "candy" but makes for a better product.
any suggestions on the FET??

I would look for something that is simple and not going to wear out like a motor. An then there is the problem of bugs.

Some way to move a switch with moving air.

 

[MrDEB]

I was thinkng a venturi

then measuring the amount of vaccum or velocity of air moving through it.
As for the two units I contemplated designing one board with two power supplies (actually 3 (12v, 5v, 4.5 battery)
home unit has a PIR where the car unit does not.
this is why I was looking at combining the battery supply /5v units as one. BUT for home, the regulator is not needed unless I have 6 AAA batteries connected to a 5v regulator?? additional cost for home unit?? but then I could have more of same pc boards made at less cost per board??
maybe utilize the LM386 in both units?
lots of options.
oh yea the car unit dosn't need the dip switches.
the vehicle speed idea is maybe worth looking at as it is perhaps a good selling point??
instead of the PIR waking up the PIC use the speed sensor to wake up Picky.
LOTS of items and options to look at.
another thought = add a zener diode to pin 14vcc of the PIC to prevent over-voltage for sure?? battery drain??

 

[MrDEB]

Egadds looked at design notes

ON semiconductor site notes AN920A/D and AN954/D
needs lots of external parts unless I am reading it wrong??

 

[MrDEB]

sensing mph

got the idea of using a tilt sensor mounted on a rod that has either just a small paddle or shaped like an airfoil.
adjusted so when vehicle is travling at say 25mph the arm moves to turn on the tilt switch??
the arm is weighted so it can be adjusted for mph.
an LED is routed to drivers compartment thus telling the driver when the unit activates
been contemplating the duel use circuit board - pretty easy to design I think.
a 2x board with componets for power supplies on one side and PIC etc on other.

 

[3v0]

I would make a PCB for each application and not have to bother with the connector(s) between the two boards. Less to buy, less to go wrong.

For the sensor I was thinking more along the line of a two springs. Keep the airfoil weight down. The less it weighs the less force movement of the car will have on it.

| spring airFoil spring |

Pressure on the airfoil/paddle will compress one spring and close a switch or move a magnet close to a hall effect sensor.

Why are you talking about 12V zenier diodes ? The LM2927 (or other automotive regulator) takes care of overvoltage and reverse voltage.

 

[MrDEB]

gun shy after killng 2 PICs

IF I had a 4.5 zener on the board connected to Vcc I might have not poped the two PICs.
I will invistage the airfoil idea.
the two seperate boards = I like the idea of one for both.
only thing different is no PIR and no dip switches on auto unit, but an amp and regulators are added.
board layout is basically the same.
connect the battery pak where the 5v regulator is connected.
QUESTION = switching to a fet INSTEAD OF A 2N2222 TO TRIGGER THE pir/pic SECTION. wOULD A fet BE WORTH THE TROUBLE AS FAR AS BATTERY SAVINGS?(oups cap lok on, sorry)
never worked w/ FETs but then again never worked w/ PICs either.

 

[be80be]

Here you a cheap workable sensor all it is is tube with a slot cut in the middle with a small led put in the slot two very lite springs to hold the ball so it blocks the leds light two ldr read the light when the car moves

 

[3v0]

On you BB a zener to protect the PIC would be OK.

It would be good if you can make one PCB and populate it different for home vrs auto use.

I would not think of switching to a FET until you find out why the 2N2222 did not work. I do not know if switching is worth the effort.

You can mock up the transistor on a BB without the PIC. Put an LED ground (short) lead on the transistor collector. Put a 1K resistor between the LED + and 5V. Gnd the emitter.
**broken link removed**
As you move the wire labeled PIN 22 from gnd to 5V the LED should light up.

The transistor on the schematic has its pins labeled E, B, and C. These pins are located on the transistor from left to right (E, B, C) as you are reading the face of the transistor with the legs down. If the LED is hooked up backwards it will not work but won‘t harm it. Pin # 22 on the expansion cable is used to control the LED.

Schematic and quote from ARobot Encoder Driven LED Application Note .

 

[MrDEB]

the 2n2222 works

I just want to mininize the drain on the batteries.
the PIR outputs 3v to the base of the 2n2222.
the collector has a 20K pull up resistor and when the PIR is triggred the emitter goes to ground thus taking pin 17 (RB2) low and waking up the pic.
your right that it may be to much bother to switch from the 2n2222 to a FET.

 

[be80be]

This would make a good accelerometer. How it works is it has three mirrors in it two on the led side of the flaps. And one on the bottom, with the LDR facing down out side of the flaps. When the car or what ever you put it on
accelerates they move back by the amount of force to make your car move. Which angles the light from the led towards the LDR. Which lowers the resistance by how much force is applied. You could also use it for sensing tilt.
The ball and spring work to see if the car moved but with flaps and mirrors you have better precision if you wanted to use it for tilt. It starts at 112K and gos down to 20k like turning a adjustable potentiometer very good control.

 

[MrDEB]

voltage regulator circuit

basic power supply
Battery power for home unit and automotive electrical for automotive use.
put on one board w/ rest of PIC circuit but connect battery only if using for home.
as for MPH sensor for vehicle use
a simple ping pong ball in a tube with a cap on one end w/ a hole in it.
other end has LDR sensor(IR?)
tube mounted at slight angle, when wind enters the hole the ballwill rise thus triggering the circuit ON
sensor could be mounted at either end of tube.
MPH sensor adjustment = adjust angle of tube. hole size to be determined

 

[be80be]

Mine don't need no wind just move the car. And you should have bigger capacitor on the output side of your regulator and you don't need 4 of them if you feed the 5 volt
from the 12

 

[MrDEB]

I wondered about that = capacitors

The unit is supposed to be triggered at say 25mph. So an accelerator sensor would turn the unit on right away.
will delete / change power sup[ply caps etc.
Am double checking the circuit boards for errors as I have one assemvbled. Just triple checking befor inserting PIC.
I might have an error on the 2n2222 polarity??

 

[MrDEB]

2n2222 in backwards??

looking at silkscreen compared to schematic the collector on Q3 is supposed connected to R8
Q2 collector is supposed to be connected to the speaker
on the PC board silkscreen the transistors are backwards??
unless the data sheet is wrong (not)
the express pc is wrong??
or am I reading the data sheet wrong.

 

[3v0]

You can get the same transistor with different pinouts.
First choice is the datasheet from where you purchased the transistor. But it too can be wrong. (Been there)

This is not fun but is the was it is.

 

[MrDEB]

data sheet from supplier

Mouser
I seem to recall that one can test a transistor by treating it like a diode.
using a diode tester setting on DVM
haven't tried this??
I think the silkscreen is wrong but I drew up a sch with just a transistor and it layed out on the PC board portion of the program correctly??
latter today I am going to invistage further.
Have a scout outing today. A cub scout fun day. about 60 scouts from other packs get together for fun and games.
gonna look for a ping pong ball as well and do some testing to see if my theory works.

 

[be80be]

If you wouldn't take screens shots and just export your file change it to a .png in paint and post that it would be easy to to see what is wrong. But every time you screen shot it you post half of it. Have you ever had a deer hit your car I had one hit my service truck the boy driving it just pull out of the driveway . He didn't even get to 25mph. But any way what i posted can tell you how fast you car is going. It cost me $4800.00 to fix
my truck them deer in Ky. are like horses Big deer.

 

[be80be]

Here a simple transistor tester just set it for a npn or a pnp press the button
and if the 1 led lights it's a good npn if the 2led on the left lights it's a good
pnp no led lights it's bad. It will tell you what kind you have. To set your transistor just hold the transistor in you hand pins down looking at the numbers and it Emitter before Collector EBC easy to remember base is in the middle Good for about all of the TO-92 npn and pnp

 

[MrDEB]

I will post in png file

as far as the transistor, I have been bread boards using the data sheet pin out and they work so I guess the express pcb is wrong.
will have to build a transistor tester.
THANKS!
can you harvest road kill in Ky?

 

[Triode]

Im going to jump in with another non sequitor:

I'm all but done making my junebug (I was out of town for a week, it hasnt taken me that long) I just want to make sure I dont do something stupid, gnd and u5v are just supposed to be wire loops to make testing and stuff easy right? I wasnt supposed to have a part for that was I? I can see the two points for each one are conected on the board so I dont see what else they could be. I'll be powering it up soon. I hope it works.