You can buy these chips at most any electronic parts place, I bought the 75HC244 at Fry's $1.89 which si HIGH, Mouser.com has them for like .59 cents i think.

Radio Shack carries some chips but not sure on these or something that would work, you need a Non-Inverting logic chip.

The 244 and 541 are Octal chips, ONE chip will operate 8 servos.

Very common chip.

Smart Fly, I agree, we tested one and the output SIGNAL voltages were 4.8 v p-p. We didnt check the min input signal, they use the hct 541 chip and the HCT series states 4.5-5.5 so im not sure about that.

To me the HC series would have been a better choice but theres MANY different chips that would work fine.

What do you do with the chip? How do you wire it in? Is there additional circuitry? Schematic anyone?

Thanks.

Superdave,

While the HCT devices have a tighter supply voltage specification (4.5V - 5.5V) then the HC devices, they also have a switching threshold of 1.4V vs. a switching threshold of 2.25V for the HC devices. Given this, the HCT devices are a better choice for buffering the FASST outputs, which some have measured as below 2.5V. Too close to 2.25V for my comfort - 1.4V gives a nice, even noise margin for 2.5V signals - which is what the HCT were designed for...

Bob

Wocketman,

You can use the HC244 or HC541. The pinouts of that chip are shown below. Pin 20 is tied to the receiver power, pin 10, 1, and 19 are connected to receiver ground, and pins 2-18, 4-16, etc. are the input/output pairs.

Actually, the HCT series devices are better suited to FASST signal output voltage as described above, but you have to use them with a regulator for receiver power - as the SmartFly units do...

Bob

edited to correct the mistake Dave pointed out...

Bob you may very well be right, I know each has good and bad.

I believe your wrong on how you said to wire it up, CE on each bank should be grounded, not tied to +.

Its late and ill double check tomorrow.

1 chip, 8 servo extensions cut in half will make a buffer for 8 serovs.... a small PC board and socket makes so easy.

Dave

Futaba Product Advisory- R6014FS Receiver

Whereas many previous receivers offered a signal output of 3.0 Volts, the latest generation of IC’s has been designed to operate at lower voltages in order to increase their operational speeds. The R6014FS receiver utilizes such an IC and, as such, the nominal output voltage of the R6014FS receiver is 2.7 Volts.

While this variance in the output voltage will not affect most equipment in use today, it has been brought to our attention that some manufacturer’s products are not capable of operation with the lower voltage. That is, they will not operate below 3.0 volts. Some examples of what we have had reported thus far includes sequencers, cut-off valves, older servo designs and some recent non-Futaba digital servos.

Some battery back-up devices might have difficulties with the lower operational voltages as well, although they might not appear to initially. One such device functions perfectly on the ground and during a range check, yet when the operational temperature reaches 50 C (122 F), the device actually requires 2.8 Volts in order to function properly. As such, the servos will cease to operate properly.

Many of the manufacturers are updating or refining their products to ensure compatibility with the lower operational voltages. Should you have any questions about the operation of such peripheral items we strongly suggest that you contact the manufacturer directly.

If you have already purchased items which are not capable of operation below 3.0 Volts, we suggest that you either replace the item with an updated version or utilize a device to increase the voltage accordingly. There are a number of readily available devices that may be used to increase the voltage such as: ElectroDynamics’ Buffer-Amplifier Interface, Duralite’s PowerBox (manufactured within the last six months), EMcotec’s DPSI products, etc.

Which RC gear works at 500C degrees ?

TURBINE

Well if you put your servos or reciever in the turbine's jet blast.. signal voltage is really your last concern !

I was getting a Power Expander anyway

Afterburner,
on another thread, a response from Robbe mentioned 50 deg C, not 500 deg C... I'm not sure which is correct though - one is obviously a typo...

My last model I've only used Hitec servos for secondary functions, and not on flight controls. Then again, I'm runnig 4.8 v on the secondary servos, and 6.0v on everything else with an i4c isolator. I haven't ordered my 2.4 module/receiver for my 14MZ yet, but it is unfortunate we may have to screen our servos for compatability. []

Edit: Added link - post #31 for the 50C comment.

http://www.rcuniverse.com/forum/m_70...tm.htm#7100927

Who make this model of amplifier?

Guys, this was a typo.....it should read 50 degrees.

Hi all,

Please look at post 742

http://www.rcuniverse.com/forum/m_61...30/key_/tm.htm

Information on the powerbox and R6014 compatibility strait from Emmerich Deutch.

Cheers,

Mick.