I have some flashing LED's and just want to enquire if the frequency they flash can be changed. Also can they be connected in series and do they require a series current limiting resistor?

Many thanks

 

No specs, manufacturer, source, or photo? Tough to guess what you have.

 

If the LEDs flash with application of power, then freq. is fixed & no change is possible. In series results might be strange, un intentional operation. Yes , current limiting is needed.

 

No specs, manufacturer, source, or photo? Tough to guess what you have.

Sorry

I get most of my components from Mantech in South Africa

Below are the links to the data sheets

http://www.mantech.co.za/Stock.aspx?Query=14m6056and
http://www.mantech.co.za/Stock.aspx?Query=14m4498and
http://www.mantech.co.za/Stock.aspx?Query=14m6007and
http://www.mantech.co.za/Stock.aspx?Query=14m5996and
http://www.mantech.co.za/Stock.aspx?Query=14m5981and

 

I bought similar ones by mistake and no, you can't change the frequency varying the voltage; you will only get some colors not working at lower voltages (e.g. blue).

Besides that, they work as any other LED; so yes, you can connect them in series, and the resistor depends on the voltage applied.

 

If they are connected in series, you will see some strange results, if anything at all. If you want several LEDs to flash in unison, one can make a series string of a resistor, a flashing LED and several standard, non-flashing LEDs. The quantities and resistor values depend on your design and it's power source.

If this is not what you're looking for, Nevermind.

 

Thank you one and all for your advice and assistance.