welcome to the pcb cooking show where today i'm going to show you how i made this new pcb hot plate if you remember a few months ago i made this prototype which talks less given all the problems that i've had so let me show you how i try to fix them i started with the track resistance last time i messed this up because i based my target resistance based on thermal properties of flexible pcbs so my goal was to achieve NUMBER_TOKEN ohms which i also simulated incorrectly because the actual resistance was measured to be NUMBER_TOKEN ohms after the video i found that the error in my simulation was including the plating thickness to power the hot plate with like NUMBER_TOKEN volts the target resistance should be much lower in fact i verified this with some research and i found that NUMBER_TOKENd printed heat vests usually have a resistance that is less than two ones so i recalculated everything with a one ohm target to find the new properties of the track the next thing i had to figure out is how to make the pcb more rigid although the first pcb had an aluminium core it was still bendy it also expanded with heat and the air slots were creating a temperature difference which was creating a problem for small sized pcbs so i took the decision to remove all the slots and make the pcb a little bit thicker this would obviously increase the thermal mass but i tried to mitigate this by selecting aluminum with better thermal conductivity my next goal was to design a beautiful board using altium designer i decided to go with a heating area of NUMBER_TOKEN centimeters diameter which is supported by an air circular ring to hold the stand off feet this had to have exposed copper so that can be kept at a cool air temperature passing the thermal track within the circular outline was a little bit tricky but altum's interactive length tuning feature made things really easy but also let me add some warning signs on this little screen for extra safety if you'd like to test this pcb design software for free you can click the link in my description and if you're already an altum user or would like to purchase a license you can get NUMBER_TOKEN percent off pcb friday
START_SPONSOR_TOKEN the link in my description and if you're already an altum user or would like to purchase a license you can get NUMBER_TOKEN percent END_SPONSOR_TOKEN