?? about data sheet specs

[MrDEB]

Trying to learn something about transistor switches etc. SEE RANDOM CABINET LIGHTS post
I attached a data sheet for a cd4029 counter. want to drive a transistor into saturation for best results but without frying the 4029 outputs.
looking at the output current am I to assume that the 4029 will source 1.6ma at 10v supply?
at 15v the 4029 will source 4.2ma??
I looked over my schematic and assume that I need to have the load connected to the emitter on a 2n2222. I have it connected to the collector.

 

[Leftyretro]

Trying to learn something about transistor switches etc. SEE RANDOM CABINET LIGHTS post
I attached a data sheet for a cd4029 counter. want to drive a transistor into saturation for best results but without frying the 4029 outputs.
looking at the output current am I to assume that the 4029 will source 1.6ma at 10v supply?
at 15v the 4029 will source 4.2ma??
I looked over my schematic and assume that I need to have the load connected to the emitter on a 2n2222. I have it connected to the collector.

One is safer designing to the minimum specification (it's a kind of a guaranteed specification) of 1.3 and 3.4ma. You might consider using a MOSFET 2N7000 instead of the 2N2222, as it requires no steady gate current, are cheap and I would have the load on the drain.

https://www.electro-tech-online.com/custompdfs/2009/02/2N7000.pdf

Lefty

 

[audioguru]

The datasheets from Texas instruments show the typical and minimum output current of Cmos logic ICs when the supply is 5V, 10V and 15V.
Care must be taken at the higher supply voltages because the max allowed dissipation for one output transistor is 100mW (over the full temperature range).

The typical output current when the supply is 10V is 13mA when the saturation voltage loss is 5V so the dissipation is 65mW. The minimum current is 7mA.

When a typical device directly drives a 2V red LED when the supply is 10V results in a current of about 14mA and the output transistor dissipates 112mW which is fine when the ambient temperature is room temperature. No current-limiting resistor is required.

 

[MrDEB]

better to go with MOSFET??

not sure if mosfet is way to go??
need to learn moore about as all this info is overwelming at best.
will do some web searching for sample circuits as I did for the transistor switch.

 

[audioguru]

Most LED chaser projects use the output of a Cmos logic IC directly driving LEDs without using a transistor.

The datasheet for the Cmos logic IC shows a low output current when the voltage loss is low when it is used for a logic voltage. The datasheets from Texas Instruments show that if you allow a higher voltage loss then the output current is much higher.

I can't remember which LEDs you are using so I don't know if only 14mA will be bright enough.
Recently I finished two projects with Luxeon Superflux LEDs that have a max continuous allowed current of 70mA and I have them extremely bright at 53mA.