Work it out.
Calculators
Ohm's law and power
Ohms lov · effektloven
Two resistors – series or parallel
Seriekobling · parallelkobling
DPMO and yield (soldering quality)
IPC-9261
Stencil aperture – area ratio and aspect ratio
IPC-7525
Solder paste – deposited solder volume per stencil aperture
SAC305-legering — producentdata (tjek datablad)
Reflow profile – heating and cooling time
IPC/JEDEC J-STD-020E
Time above liquidus – from belt speed
IPC/JEDEC J-STD-020E (blyfri TAL 60–150 s)
Moisture sensitivity (MSL) – remaining floor life
IPC/JEDEC J-STD-033
Ionic cleanliness – ROSE test contamination
IPC-6012E / IPC-TM-650 2.3.25
ESD wrist strap – resistance test (pass/fail)
ANSI/ESD S20.20 + S1.1 (håndledsrem)
Components back on the tape reel
EIA-481 (komponent-pitch på carrier tape)
Cable resistance and voltage drop
Ledningsfysik (kobbers resistivitet, materialehåndbogsværdi)
RC time constant – charging/discharging a capacitor
Kredsløbsteori (RC-kredsløb)
Voltage divider with two resistors
Kredsløbsteori (spændingsdeler)
Series resistor for LED
Kredsløbsteori (Ohms lov anvendt på LED)
SMT line: bottleneck and capacity
Technical appendix: assess bottleneck issues · optimise automatic production processes
Solder paste for an order
Pasta density from metal content (manufacturer's datasheet, typically 88–89 weight % for type 4) · technical annex: plan a work process
Tools that work in all subjects
Whatever your programme is called, these tools calculate the same — Pythagoras, area, percentages and units are not tied to one trade.
- Pythagorasa² + b² = c²Find the missing side, set out a right angle, check whether a room is square, and find the space diagonal.
- Area and perimeterm²Rectangle, triangle, trapezium, circle and composite shapes — area and perimeter.
- Volume and surface aream³ · lBox, cylinder, cone, sphere, pyramid, prism, pipe and frustum — also in litres.
- Percent%Percentage of, how many per cent, percentage change, discount and VAT.
- Scale and ratios1 : 50From drawing to reality, area and volume to scale, the rule of three and dividing in a ratio.
- Unit convertermm ↔ mFrom mm to km, Pa to bar and kB to GB — with the unit staircase.
- Time calculations and the clockt : minTime between two clock times, add time, and 1.75 h = 1 h 45 min for the timesheet.
- Slope and fall% · ° · 1:xFall from level to level, in per cent, per mille, degrees and mm per metre — and the height difference.
- Material consumption including wastem² + %Boards, paint, battens at c/c spacing and packs — for a composite surface or a whole room, with waste.