Switch frequency in rc car

[ashnu_tnj]

I have designed an RC car that transmits and receives at frequency of 434Hz..now i have to modify that to work in some other frequency also.like i have to make sure that it works fine in both the frequency(either at a time).please help.

 

[duffy]

434 Hz? I think that's probably a typo, isn't it? 434 kHz still sounds too low. 434 MHz? Need to describe your circuit better, maybe upload a schematic. Usual technique is to swap crystals, but I think a crystal that ran at 434 Hz might be bigger than the RC car itself!

 

[shub]

Series-Parallel Resonance

Hello there, I am new to the forum and it won't let me make a new thread- so I have "hi-jacked" this one that didn't have many replies. If anybody would like to make me a thread, that would be great too. Here's my troubles:

I am trying to complete an exercise in my Linear Circuits class. I figured out how to do Series Resonance and I've mostly grasped Parallel resonance (just inverting some numbers), but I am thrown for a loop on this Series-Parallel combination. My textbook is making my head spin!

I have an image of the circuit and an accompaying word doc for the table I am supposed to fill in. If anybody would be willing to complete a sample row using one of frequencies with a description of the forumulas, so I can finish the rest of the table on my own, that would be wonderful.

**broken link removed**

Basically, we change the frequency of Vs in accordance with the table values. The resistor above the coil is supposed to represent the winding resistance. I don't know, but I am assuming the resistor that is in series with the parallel combination at the start of the circuit is a Thevenin resistance?

I tried making an equivalent parallel circuit of the coil with its resistance as an Leq and Req after I found the Q of the coil. But I didn't know what to do from there.

The word doc:http://www.geocities.com/wrmiro/Presonant.doc

Thanks in advance for any volunteers that come forward.