single led blinker/parking without relays

Hi, I want to use the single LED in my marker/corner light(s) as both turn signal & blinker. Here's what I'm looking for it to do:

1. Blinker on, Parking off = Blinks.

2. Blinker off, Parking on = On solid.

3. Blinker on, Parking on = Blinks.

Now, here's the difficult part, I don't want to use relays! Instead what I want to do is use a few small JFET transistors (NTE457), diodes, & resistors. for a more compact setup. From what I understand JFET transistors are normally 'on' and turn off once voltage is applied to the 'base'.

Here's what I've come up with, but I'm not yet sure on the resistor needed.

OR, if possible using an Integrated Circuit, NTE858M which has dual JFET's... Really not sure about this one though.

I do NOT mind that the blink is 'offset' when the parking light is on.

Thanks,

Andrew

Well, that's why it's configured so that if one see's voltage, it shuts the other off. The response time should be high enough that there won't be any issues there either (or so I'm guessing).

When both JFET's happen to be on... both the blinker & parking are off. So it's a non-issue (again, so I 'think'). I'm unsure what the actual current for 'G' is, but according to NTE (the MFG) it's max rating is .010 amps, and it will probably be a lot less (guessing). 

It may be a simple circuit, but I have spent 2-3 days doing research on available semi-conductors to 'find' the JFET's and get a basic understanding of how they work... and even then I didn't come up with the above idea immediately. I spent a solid day trying to figure something out and came up with nothing but either a 3 relay setup (for both L&R) or 4 relays (2ea side). This came to me the following day after I gave up for the night.

Andrew

Again, just spent some time looking over NTE's info/site.

http://nteinc.com/Web_pgs/FET.html & http://www.nteinc.com/specs/400to499/pdf/nte457.pdf

Near as I can tell, the current/amps necessary to bring DS voltage to zero varies from .001-.005 amps. To quote NTE, "Drain Current Zero - Gate Min-Max (mA) : 1-5. And average is 3 mA." Leaving me to think total amps necessary is going to range from .016 A (min) - .023 A (max).

Just had another thought, do I need to take into account the resistor/resistance that's built into the wedge style LED? I just verified they are constructed with both a resistor and additional diode for safety. Measured 447 ohms with a multi-meter, which is right at the 5% tolerance limit of the standard 470 ohm resistors used when wiring in single LED's.

Or maybe not, since the Transistor that is ON is setup with the resistor & GD in parallel with the one being shut OFF. That would mean it's not a problem,  correct? As both the LED & the GD seeing voltage will be receiving 12v due to the parallel circuit there. Wouldn't that mean the current would be split on the two legs then recombine where the two D's combine and voltage would remain as 12v for both (If I'm thinking about this right).

Andrew