Ytec3D Forum

I would encourage people to use L6452 for HP45, if you mainly want to drive the HP45 not just for fun with circuits. Although the ST's support is the worst, I'm still thankful as they do provide this chip. Look at the waveform I captured, the edges were so clear, that was with 33ohm load.

I'm still working one the vboost/vsetup connection. As a partially switched on transistor can get very hot and even burn itself. Also, if the voltage is not right, the switch timing can change.

@Mahsa could you please be more specific with the vboost connection you suggested? even a pencil diagram would be very much appreciated.

David, how do you address 22 addr lines? You use both channels A and B and switch between channels to drive all nozzles? The switch is fast enough?
We'd all appreciate if you show how you connected the IC to the printhead.

@david

I have a vague idea how the boost might work. Do you measure a diode between StepUpBoost and VstepUp? If so, in which direction does it point?

My guess is that an inductor is required between supply and StepUpBoost, and a capacitor on VstepUp to store and smooth the boosted voltage.

But this in only a guess, based on the fact that StepUpBoost looks like a high current switch point due to the dedicated ground connection right next to it. But it could also just be a gate driver for an external fet.

If you connect a 1K resistor between 12V and StepUpBoost, do you see any switching on it?

Thank you,
Errol

@david

this is the schematic of vboost.

Hi all,

I've attached my driver design. I still have some work to do on the schematic but i'm close to my final design though.
Since I don't know how to use the internal stepup part of the L6452, I used LT1930 for VstepUP. It's enough for the low current input of the L6452.
I found it difficult to mess with its internal ADC/DAC so I'll read the HP45 resistor with ATMega. At least, I already have all the libraries for ADC.
TH1 thermistor will be used to read room temperature for calibrating head temperature in cartridge setup routine.
For now I really don't know if I have to lower primitive Vc inputs for adjusting firing energy. The datasheet states this voltage must be in 10.5...12.5V range. I suppose I'll lower the energy by trimming /LONGPULSE width.
I really don't know if this design really works but it's my opinion.
As a bonus, I packed in this file the component library for L6452 I designed.
The Vr,Va and Vc voltages of the driver will be tied together on the J3.
Please correct me if you find any error (beside the typo on the label - L6542 instead of L6452).

@dragonator

you can try CD4505bpwr. this ic is used for Printer.

@davidk for those unused input pins on L6452, may I suggest connecting them to the ground.

Thanks. You're right, inputs should ALWAYS be tied to a certain level.
Did you use its internal ADC?

@David, can you confirm that this wiring is correct for the L6452 (minus the inputs to ground). I have yet to try it but when I do it is nice to have a reference.

@Mahsa: I tried to find your component, but I got no matches on the internet.

I would love to post actual updates, but my PCB's are still in transit and it is currently 30C in the Netherlands and it is too hot for me to think. My first next step is the new 3D printed carrier for the HP45. The old one sucks, and I want a better one.

@dragonator

this is the link of datasheet
http://www.ti.com/lit/ds/symlink/cd4504b.pdf