Let's Make Robots!

relay

The Garden's fountain for the dogs based on Arduino.
Using a
Dog Fountain The Garden's fountain for the dogs based on Arduino Introduction The project started with 2 dogs in a garden and bowls always empty or fill with … Read more
Gives all directions for two motors
I designed this circuit for those interested in controlling motors that require a lot of Amperage, but have gotten frustrated over trying to create a MOSFET … Read more
Walk forword,back.left,right,balance one leg, up-down 1 or 2 leg,Turn right-left,Control With Bluetooth
Using a
My new Biped Robot "Red-Dragon V3"   what's new -Remove the camera Read more

Relay vs H-bridge question

most of the time I use an L298D motor driver IC for controling motors. However i find that the 1+ voltage drop is anoying. Some motors just dont go fast enough. 

Using a 7.2V power supply, leaves about 6V going to the motors and, as I understand it, the L298D is not designed to take in higher voltages. Although I think it can handle quite a bit if you cool it properly.

My first PCB

Hi guys,

I started on some unfinished projects again but I could use some advice. I'm trying to build a board for the mini reef that can switch 6 devices (solenoid valves) at 12v DC with the PIC/Prop controller. I'm using diptrace for this as this seems to be the favorite choice. So far I love it.

I came up with the below but I'm running into some problems with the traces. Maybe someone can point out the right direction as I think that it must be possible to cross over a line (with some electonic component maybe)? The red circles are the problem areas.

Hybrid H bridge single relay configuration

So I have been brainstorming H-bridge designs for a 5V motor with 5A stall current.  I want max speed from the motor off 4xAA batteries, so I am considering using a high side relay vs a high side transistor.  I would like the H bridge to:

A mechanism with a one-track mind.
This is something I built a while ago.  I won't call it a robot as it's very limited in its function - It only knows about FORWARD!  It was just an idea which I … Read more

A mini relay like chip?


Here is the setup, I need a picaxe to "push" 2 buttons when it receives a high digital input. 
I will be using a picaxe08M and will have 2 digital inputs(2 buttons) and to digital outputs to triger the relay.
 
I need somethink like a relay but much smaller, about the same size a the picaxe chip.
 
It only need to handle 5V.
 
Anybody know of something that would do the job ? 

How to use two analogue devices with only one analoque input?

For now it's theory, it's for a future evolution of a future project (yeah i know that's two "future")
Ok actually i'll need 3 analogue inputs (one SRF05 ultrasonic rangefinder and one 2-axis accelerometer), but the 18x picaxe chip has only two. So basically, i need to find a way to share one of the inputs. As i won't need to read the all inputs at the same time, maybe it's doable.

So two ideas came to my mind, each one with its pros and cons.


First idea : a SPDT relay.

With that, two solutions :

Price: $3 USD
Relays are an alternative to motor-controllers. They do consume a little power from your battery when in either on or off position (turned on) - but they also do … Read more

How to wire a relay

Hi,

I bought some relays, just to see what could be done - perhaps sometimes an alternative to a H-bridge.. or perhaps make a light-show or something, they are very cheap, so I thought "hey, let's see".

I got some of these AZ8222, and the documentation is thorough.. but look in the bottom of the manual - what on earth is supposed to be hooked up with what?