| C1 | .47 uF | decoupling and energy storage, part of C1/C2/R1 network which reduces laser output if the LASER_EN drive has a duty cycle of more than 20% and limits pulse width to approx 30 uSec |
| C2 | .1 uF | see C1 |
| C3 | .01 uF | part of C3/R4 network to extend rise time of current through laser diode so that APC system prevents overshoot |
| C4 | .1 uF | decoupling, bypassing for wiring arrangements in which the shield of the TXD conductor is used as the +12V supply conductor |
| C5 | 10 uF 16 V tantalum | decoupling |
| C6 | .1 uF | decoupling |
| C7 | 10 uF 16 V tantalum | decoupling |
| C8 | .1 uF | decoupling |
| C9 | 10 uF 16 V tantalum | timing capacitor for 555 which holds the CS8130 in CONTROL mode for a few seconds after power-up |
| C10 | 10 uF 16 V tantalum | decoupling |
| C11 | .1 uF | decoupling |
| C12 | 10 uF 16 V tantalum | CS8130 reset circuit timing capacitor |
| C13 | 18 pf | crystal loading capacitor |
| C14 | 18 pf | crystal loading capacitor |
| C15 | 10 uF 16 V tantalum | see C4 |
| C(DB9) | .1 uF | coupling capacitor, mounted inside DB9 connector if independently shielded
twinlead is used for the cable from the UPNLT to the computer and power supply |
| D1 | 1N4004 | reverse polarity protection |
| D2 | 1N4148 | discharge path for CS8130 reset capacitor |
| D3 | 1N4148 | reverse polarity snubber |
| LDPD1 | HL6720G | Hitachi 670 nm 5 mW laser diode with inbuilt photodiode |
| LED1 | 3 mm red | voltage regulator |
| LED2 | 3 mm red | CONTROL mode indicator |
| PD1 | SFH213 | receiver transducer |
| Q1 | BC327 | photodiode current amplifier |
| Q2 | BC337 | laser diode current regulator |
| Q3 | BC327 | RXD line driver |
| Q4 | BC337 | TXD line receiver |
| R1 | 180R | current and duty cycle limiter, see also C1 |
| R2 | 1K | dropping resistor for LED1 |
| R3 | 1K | Q1 load resistor |
| R4 | 1R5 | see C3 |
| R5 | 4K7 | laser diode forward biasing resistor |
| R6 | 470K | timing resistor, see C9 |
| R7 | 1K | current limiting for LED2 |
| R8 | 10R | decoupling for analog +5V rail |
| R9 | 4K7 | CS8130 reset circuit timing resistor |
| R10 | 4K7 | Q4 load resistor |
| R11 | 4K7 | CS8130 protection resistor |
| R12 | 4K7 | Q3 base current limiter |
| R13 | 1K | TXD line load resistor |
| R14 | 4K7 | Q4 base current limiter |
| R15 | 47R | Q3 protection |
| R16 | 180R | Q3 load |
| Rtest1 | 47R | Laser diode simulator resistor, used only during initial adjustment |
| Rtest2 | 47K | Monitor diode simulator resistor, used only during initial adjustment |
| U1 | MC78L05ACP | +5V voltage regulator |
| U2 | NE555 | Timer which hold CS8130 in control mode for a few seconds after power-up.
Note that use of some other versions of the 555 can result in C9 retaining its charge for many seconds after power down, so a power-up within that period will give a shortened CONTROL mode time for the CS 8130 |
| U3 | CS8130-CP | DIL version of Crystal's multistandard transceiver chip. This IC performs most of the complex, sensitive and critical functions required for the laser transceiver. |
| VR1 | 50K | laser monitor diode feedback adjustment |
| VR2 | 100R | laser current limit adjustment |
| X1 | 3.6864 MHz HC18U |
transceiver clock crystal |
| Z1 | 5V1 250 mW zener | 5V rail clamp |
| lens assembly | Collimating lens and laser diode housing to suit 9 mm laser diode |
| socket | 20 pin .3" DIL socket for U3 |
| socket | 8 pin DIL socket for U2 |
| terminal block | 4 way, 5 mm spacing |
| saddle | 3/8" copper saddle to secure laser diode assembly to PCB |
| shield | 25 mm x 25 mm x .005" brass shim, shield for PD1 |
| screws | 2 off M3.5 x 10 mm, to secure saddle to PCB |
| nuts | 2 off M3.5 |
| PCB | UPNLT, 55 mm x 87 mm single sided, printed component overlay |
