Samvinna
LIST
FEGURÐ OG VELLÍÐAN
HANDVERK
MENNING OG SAGA
SKEMMTUN
UMHVERFI
MATUR OG DRYKKUR
ÖFUGVERKFRÆÐI
VÍSINDI
ÍÞRÓTTIR
TÆKNI
KLÆÐANLEG TÆKNI
Digital Tachometer: Hand-Held Contact Type That Holds Its Reading (Sugiyama, Shimpo, US 4,000,465, 1976)
A hand-held digital tachometer. You press the contact head on its shaft against the end of a turning shaft and push the thumb button; a slotted disk inside chops a light beam into pulses, and the pulses counted in a fixed time, set by a quartz clock, appear in the window as the speed. A latch holds the reading after you take the tachometer away, so you can read it even where you could not see the window while measuring.
Result: a contact tachometer that shows revolutions per unit time and keeps the last reading.
Source: Y. Sugiyama (Shimpo Kogyo), US 4,000,465 (1976). Unknown: the number of holes, the clock, the gate time and the circuit details. Picture: the patent drawing.
Lengra kominn
Unknown
Leiðbeiningar
1
1
Make the housing and measuring shaft
Make the housing and measuring shaft
Make a cylindrical housing to hold in one hand, with a window in its side for the reading and a push button for the power switch where the thumb falls. Run a measuring shaft out of the front end in bearings and fit a contact head on its tip to press against the shaft being measured. Not given: materials, sizes. Ours: aluminium tube, a ball bearing.
Efni fyrir þetta skref:
Álrör1 housing
Óþekktur málmur1 measuring shaft
Kúlulega1 stykki
Óþekktur efniviður1 contact headNauðsynleg verkfæri:
Málmrennibekkur
Handbor
Óþekkt mál2
2
Make the pulse generator
Make the pulse generator
Fix a disk on the measuring shaft with a ring of small holes evenly spaced near its edge. Put a light source on one side of the disk and a photodetector on the other: each hole passing makes one pulse. Shape and amplify the pulses. Not given: the number of holes. Ours: an LED and a photodiode.
Efni fyrir þetta skref:
Óþekktur efniviður1 slotted disk
LED-úrval1 light source
Ljósdíóða (BPW34)1 photodetector
Viðnám1 settNauðsynleg verkfæri:
Handbor3
3
Build the counting circuit
Build the counting circuit
Divide a quartz oscillator's clock down to gate pulses one unit of time long. Pass the measurement pulses through an AND gate during each gate pulse into a counter. At the start of each gate pulse a reset pulse clears the counter. After the gate pulse ends, the first measurement pulse that arrives triggers a latch pulse that loads the new count into the display. If the head has been taken off the shaft, no pulse arrives, no latch pulse is made, and the display keeps the last reading until the next measurement or until the power is switched off. Not given: the clock frequency and gate time. Ours: logic ICs and a seven-segment display.
Efni fyrir þetta skref:
Prentplata1 stykki
Kvarskristall1 stykki
Úrval rökrása1 divider, AND gate, counter, latch, reset
Rekill fyrir sjöhlutaskjá1 stykki
Fjögurra stafa sjöhlutaskjár1 stykki
Lóðtinsvír1 as neededNauðsynleg verkfæri:
Lóðbolti4
4
Power it and measure
Power it and measure
Fit the battery and the thumb button as the power switch. Press the contact head against the end of the turning shaft so it turns with it, push the button, and read the revolutions in the window, now or after you take the tachometer away.
Efni fyrir þetta skref:
Rafhlaða1 stykki
Þrýstihnappur1 stykkiNauðsynleg verkfæri:
LóðboltiEfni
15- 1 housingStaðgengill
- 1 measuring shaftStaðgengill
- 1 slotted diskStaðgengill
- 1 light sourceStaðgengill
- 1 photodetectorStaðgengill
- 1 settStaðgengill
- 1 stykkiStaðgengill
- 1 stykkiStaðgengill
- 1 divider, AND gate, counter, latch, resetStaðgengill
- 1 stykkiStaðgengill
- 1 stykkiStaðgengill
- 1 as neededStaðgengill
- 1 stykkiStaðgengill
- frá$0.51
Efni úr tengdum teikningum
Þessi teikning býr til
CC0 opinbert ríki
Þessi teikning er gefin út undir CC0. Þér er frjálst að afrita, breyta, dreifa og nota þetta verk í hvaða tilgangi sem er, án þess að biðja um leyfi.
Studdu smiðinn með því að kaupa vörur í gegnum teikningu hans þar sem hann fær þóknun smiða sem seljendur ákvarða, eða búðu til nýja endurskoðun á þessari teikningu og tengdu hana sem tengingu í þinni eigin teikningu til að deila tekjum.