The Engineering Projects

where to find a pulse relay

I have a thermostat project which run from 2AA batteries
The microprocessor has a minimum consumption current
In fact the whole project run in just 1-2 miliamps.
The big issue is the output of thermostat.
Most thermostats, to conserve power , and change the battery maybe once a year , use latching relays.
2 coils take too pins from micro
1 coil is complicated to drive
I heard about pulse relays. One pulse = ON; take the power out and still ON, like a latching relay. Next pulse, on the same line, turn it OFF.
I found circuits to drive 1 coil latching relays, but most of them use capacitors, which of course will drain my battery
I need a suggestion of a manufacturer for this PULSE relays.
Contacts 2 A, coil 5-12 VDC
Thanks

how to write a mikroc code for ultrasonic sensor hc-sr04

hi :)
I want to write a mikroc code for ultrasonic sensor hc-sr04 and I need help :eek:
I am using pic16f876a

I am using ultrasonic sensor above my robot ... I want to make my robot go forward when the echo pin got signal and if the distance between my robot and the other one 50 cm or less

couls you plz help me ??

Soft start dc motor controller

Hi All,

I am looking to build a dc motor controller for a model ski lift. at present it only has an "On Off" switch, I would like it to include a soft start, reverse and half speed switches (push button type).
The motor drags about .6 amp and is a 6 volt dc type.
The idea is to give the model full automation and realisim,

any help would be great

Rotation detection sensor with schematics

Hi All,
I need to know the mechanical sensor or other sensor which can detect the rotation of chain.
When the rotation of chain stopped it should trigger alarm using 24v buzzer.
Kindly help me to over come this circuit.

ET-ROBOT 877 program follow line

Hello

I received an ET-ROBOT 877 kit, which seems very interesting. I would appreciate you could indicate me where can find a program to control the robot following a line on the floor. I saw a youtube video about it, but can´t find a similar program. Can I buy it ?.

Thanks for your attention.

cancer defeating nanobot for real

there in the news some australian scientists have made magnetically controlled calcium fluoride nanoparticles that give off nascent oxygen near cancer forming cells when exposed to x-rays killing cancerous cells in the reaction a breakthrough after IBM made pathogen sticking nanoparticles but failed.

Detecting an external resistance on a motor

We are building a very cool project for school (x-wing fighter) with functional cockpit canopy that opens and closes by linear actuator (Arduino, relay, limit switches, etc.). We cannot figure out an efficient way to detect resistance/obstruction while the canopy is closing but before it reaches the limit switch (i.e. kids hand or leg is in the way). the actuator can impose 250lbs force and definitely do not want a child getting squashed in there.
it should be fairly easy solution since all automatic trunks for vans have this feature - door stops as soon as it detects an extra resistance. One guess is that it detects when motor starts drawing too much current? If this is correct, how does it handle the fact that the motor naturally would draw much more current when the door is horizontal (extended) as opposed to vertical (close to being closed)?
Or is there another way an external resistance is detected? thanks in advance,

flying probe test

Hi,
I am an engineer student and I wish build a flying probe test for PCB (with two probes).
I have a python file that contains the positions of the components on the PCB.
I don't know what kind of stepper motors that should I use and how can I control them with arduino /python .
Any help please
thanks.

Rotation angle of Servo???

I am working on Arduino Uno based project to control the multiple servos.

I am using Vigor VS 2 servo. As per data sheet, its output angle is >=170 degree and pulse traveling 800 to 2200 µsec.

When I give command of 90 degree to rotate, it rotate slightly more than 90 degree but when I give command of 85 degree then it is looking like exact 90 degree.

I have written simple program as written below.

Servo myservo;
int pos = 0;
void setup()
{
myservo.attach(9);
}
void loop()
{
myservo.write(85);
}

What I require to modify to get the exact angle as per program code.

Thank You,

controling stepper motors

Hello
I'm an engineer student and I want to build a flying probe test (with one probe) as my graduation project.

I want to control 3 stepper motors by arduino (3 axes X , Y and Z) and I have an excel file that contains all of the components and their cartesian coordinates on a pcb board.

I'm still beginner at arduino . I ask for the way to control the stepper motors with these coordinates .

please I need your help