# what is can protocol

Thread Starter

#### ect_09

Joined May 6, 2012
180
Hi,
hope so you are fine and enjoying your life.
i want to know about can module, its being use for communication.
but dont know how its work with number of nodes.

secondly i want to know that how can i conver DC voltage to AC .
because i used full wave bridge rectifier and IC 7805 for AC into DC conversion. but how can i convert DC into AC?

third, how tube light works.
what is the purpose of starter and chock.

Thanks,
Linda

#### ErnieM

Joined Apr 24, 2011
8,362
Wikipedia is always a great place to start an investigation.

#### sjgallagher2

Joined Feb 6, 2013
131
You can check out the other links to understand the CAN system. Converting from DC to AC, sadly, is not quite as simple as using a rectifier. In order to convert from DC to AC, you need to goes understand what AC really means. It's just a voltage source that changes from +V to -V, so while you might think of it as a sine wave, it could really be any waveform that goes positive then negative! Knowing that, the circuit for converting DC to AC is done with an inverter. An inverter is a really simple circuit, but you have to know what purpose it serves, and what kind of AC power you need out of it. In order to take a DC voltage and turn it into an AC signal you need to finick with your ideas of "ground" and common nodes. The design of an inverter really revolves around a load, as opposed to an output port. Like say, a two-port motor.

What you do is place four switches around the load. The load will have two leads, maybe they're called A and B. The first switch connects from A to +DCV, the second switch connects from B to +DCV, the third switch connects A to ground, and the fourth connects B to ground. Obviously switch 1 and switch 3 cannot be turned on at the same time, or else you'll short the DC supply to ground. What you do is close switch 1 and switch 4, connecting lead A to +DCV and lead B to ground. Thus current flows in one direction, from lead A to lead B of the load, to ground. Then you open all the switches again and close switches 2 and 3. This connects lead B to +DCV and lead A to ground. So now current flows in the opposite direction, from lead B to A.

Here's the only reasonably simple schematic I could find in the few seconds I spent looking for one:

X1-X4 are the switches I was talking about, and the LC network, transformer, and resistor are the load. It's tough to really get it from this but I hope it helps. Inverters are simple in theory, but in practice it can get a little confusing. More so with 3-phase inverters, those take some real work to "get" because there's not a whole lot of information explaining them on the web. Hope this helps!

Thread Starter

#### ect_09

Joined May 6, 2012
180
thanks for the reply.
how you can conclude the following
1)what is the difference between CAN and SPI.
2)what is the difference between CAN and I2C

Thanks

#### Microwave

Joined Oct 13, 2015
2
Linda,

The starter connects the heaters at each end of the tube to the power in series. They heat up the gas in the tube, when the tube lights up (strikes) it short circuits the starter.

The choke provides an inductive load in series with the now short circuit tube. Thus limiting the power drawn from the power supply.

#### profbuxton

Joined Feb 21, 2014
421
Connect the base of two empty tin cans with a lengh of string and , voila, you have a can module.
You "can" use it for communication by stretching string tight , talking into one can and receiver holds other can to ear.

#### Papabravo

Joined Feb 24, 2006
20,378
thanks for the reply.
how you can conclude the following
1)what is the difference between CAN and SPI.
2)what is the difference between CAN and I2C

Thanks
The primary difference is that the protocol and physical layer of CAN are robust and can be used over a considerable length of cable, such as you might find in a vehicle or a manufacturing cell. SPI and I2C are primarily designed for communications between devices on a single board in close proximity to each other.

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